WorldWideScience

Sample records for calibrated diversity assay

  1. Calibrated user-friendly reverse transcriptase-PCR assay

    DEFF Research Database (Denmark)

    Bor, M V; Sørensen, B S; Rammer, P

    1998-01-01

    We report a competitive reverse transcriptase-PCR (RT-PCR) assay and a calibrated user-friendly RT-PCR assay (CURT-PCR) for epidermal growth factor receptor (EGFR) mRNA. A calibrator was prepared from isolated rat liver RNA, and the amount of EGFR mRNA was determined by competitive RT-PCR. In CUR...

  2. Integrating diverse calibration products to improve seismic location

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, C; Myers, S; Swenson, J; Flanagan, M; Pasyanos, M; Bhattacharyya, J; Dodge, D

    2000-07-17

    The monitoring of nuclear explosions on a global basis requires accurate event locations. As an example, under the Comprehensive Test Ban Treaty, the size of an on-site inspection search area is 1,000 square kilometers or approximately 17 km accuracy assuming a circular area. This level of accuracy is a significant challenge for small events that are recorded using a sparse regional network. In such cases, the travel-time of seismic energy is strongly affected by crustal and upper mantle heterogeneity and large biases can result. This can lead to large systematic errors in location and, more importantly, to invalid error bounds associated with location estimates. Corrections can be developed and integrated to correct for these biases. These path corrections take the form of both three-dimensional model corrections along with three-dimensional empirically based travel time corrections. LLNL is currently working to integrate a diverse set of three-dimensional velocity model and empirical based travel-time products into one consistent and validated calibration set. To perform this task, we have developed a hybrid approach that uses three-dimensional model corrections for a region and then uses reference events when available to improve the path correction. This Bayesian kriging approach uses the best apriori three-dimensional velocity model that is produced for a local region and uses this as a baseline correction. When multiple models are produced for a local region, uncertainties in the models are compared against each other using ground truth data and an optimal model is chosen. We .are in the process of combining three-dimensional models on a region-by-region basis and integrating the uncertainties to form a global correction set. The Bayesian kriging prediction combines this a priori model and its statistics with the empirical calibrations to give an optimal aposteriori calibration estimate. In regions where there is limited or no coverage by reference events the

  3. Four assay designs and on-chip calibration: gadgets for a sepsis protein array.

    Science.gov (United States)

    Buchegger, Patricia; Preininger, Claudia

    2014-03-18

    A protein microarray for the early stage diagnosis of sepsis that allows the simultaneous detection of C-reactive protein (CRP) (2-200 μg/mL), procalcitonin (PCT) (0.2-50 ng/mL), and interleukin 6 (IL-6) (2-2000 pg/mL) has been developed. To enable the parallel detection of the differently abundant analytes, the low binding affinity between CRP and phosphocholine is exploited in a "low-sensitive" sandwich assay for CRP. The calibration is integrated directly on the chip resulting in a "one patient-one array" format, to provide a user-friendly and rapid diagnostic tool. Four different assay designs are introduced: (I) the classical assay that works with biotin-streptavidin chemistry, (II) the rapid assay that is performed in a single detection step, and two ultrasensitive assay designs accomplished either by (III) an enzymatic or (IV) an antibody mediated amplification resulting in high density labeling. The assay designs were evaluated by the repetitive measurement of low, medium, and high concentration levels of commercially available certified control sera. The precision was similar across all assay designs (coefficient of variation (CV), CVintra: 8-14%; CVinter: 18-34%), while the sensitivity (limits of detection (LODs)) increased by 1 order of magnitude for the ultrasensitive assays (III, IV) and the accuracy was analyte dependent but best for the classical (I) and the antibody amplified (IV) assays.

  4. Calibration-free assays on standard real-time PCR devices

    Science.gov (United States)

    Debski, Pawel R.; Gewartowski, Kamil; Bajer, Seweryn; Garstecki, Piotr

    2017-03-01

    Quantitative Polymerase Chain Reaction (qPCR) is one of central techniques in molecular biology and important tool in medical diagnostics. While being a golden standard qPCR techniques depend on reference measurements and are susceptible to large errors caused by even small changes of reaction efficiency or conditions that are typically not marked by decreased precision. Digital PCR (dPCR) technologies should alleviate the need for calibration by providing absolute quantitation using binary (yes/no) signals from partitions provided that the basic assumption of amplification a single target molecule into a positive signal is met. Still, the access to digital techniques is limited because they require new instruments. We show an analog-digital method that can be executed on standard (real-time) qPCR devices. It benefits from real-time readout, providing calibration-free assessment. The method combines advantages of qPCR and dPCR and bypasses their drawbacks. The protocols provide for small simplified partitioning that can be fitted within standard well plate format. We demonstrate that with the use of synergistic assay design standard qPCR devices are capable of absolute quantitation when normal qPCR protocols fail to provide accurate estimates. We list practical recipes how to design assays for required parameters, and how to analyze signals to estimate concentration.

  5. Multiplex cytological profiling assay to measure diverse cellular states.

    Directory of Open Access Journals (Sweden)

    Sigrun M Gustafsdottir

    Full Text Available Computational methods for image-based profiling are under active development, but their success hinges on assays that can capture a wide range of phenotypes. We have developed a multiplex cytological profiling assay that "paints the cell" with as many fluorescent markers as possible without compromising our ability to extract rich, quantitative profiles in high throughput. The assay detects seven major cellular components. In a pilot screen of bioactive compounds, the assay detected a range of cellular phenotypes and it clustered compounds with similar annotated protein targets or chemical structure based on cytological profiles. The results demonstrate that the assay captures subtle patterns in the combination of morphological labels, thereby detecting the effects of chemical compounds even though their targets are not stained directly. This image-based assay provides an unbiased approach to characterize compound- and disease-associated cell states to support future probe discovery.

  6. Contactless vector network analysis using diversity calibration with capacitive and inductive coupled probes

    Directory of Open Access Journals (Sweden)

    T. Zelder

    2007-06-01

    Full Text Available Contactless vector network analysis based on a diversity calibration is investigated for the measurement of embedded devices in planar circuits. Conventional contactless measurement systems based on two probes for each measurement port have the disadvantage that the signal-to-noise system dynamics strongly depends on the distance between the contactless probes.

    In order to avoid a decrease in system dynamics a diversity based measurement system is presented. The measurement setup uses one inductive and two capacitive probes. As an inductive probe a half magnetic loop in combination with a broadband balun is introduced. In order to eliminate systematic errors from the measurement results a diversity calibration algorithm is presented. Simulation and measurement results for a one-port configuration are shown.

  7. Standardization of serum cholesterol assays by use of serum calibrators and direct addition of Liebermann-Burchard reagent

    NARCIS (Netherlands)

    Katan, M.B.; Haar, van der F.; Kromhout, D.; Schouten, F.J.M.

    1982-01-01

    Serum cholesterol concentrations of subjects in epidemiological studies were measured after direct addition of Liebermann-Burchard reagent; results were calibrated with human serum pools assayed according to Abell et al. (J. Biol. Chem. 195:357-366, 1952). Accuracy and precision were monitored for

  8. Calibration of the comprehensive NDHA-N2O dynamics model for nitrifier-enriched biomass using targeted respirometric assays

    DEFF Research Database (Denmark)

    Domingo-Felez, Carlos; Calderó-Pascual, María; Sin, Gürkan

    2017-01-01

    The NDHA model comprehensively describes nitrous oxide (N2O) producing pathways by both autotrophic ammonium oxidizing and heterotrophic bacteria. The model was calibrated via a set of targeted extant respirometric assays using enriched nitrifying biomass from a lab-scale reactor. Biomass response...... determined by the information content of the datasets using identifiability analysis. Dynamic DO profiles were used to calibrate five parameters corresponding to endogenous, nitrite oxidation and ammonium oxidation processes. The subsequent N2O calibration was not significantly affected by the uncertainty...... propagated from the DO calibration because of the high accuracy of the estimates. Five parameters describing the individual contribution of three biological N2O pathways were estimated accurately (variance/mean

  9. Calibrating the Ordovician Radiation of marine life: implications for Phanerozoic diversity trends

    Science.gov (United States)

    Miller, A. I.; Foote, M.

    1996-01-01

    It has long been suspected that trends in global marine biodiversity calibrated for the Phanerozoic may be affected by sampling problems. However, this possibility has not been evaluated definitively, and raw diversity trends are generally accepted at face value in macroevolutionary investigations. Here, we analyze a global-scale sample of fossil occurrences that allows us to determine directly the effects of sample size on the calibration of what is generally thought to be among the most significant global biodiversity increases in the history of life: the Ordovician Radiation. Utilizing a composite database that includes trilobites, brachiopods, and three classes of molluscs, we conduct rarefaction analyses to demonstrate that the diversification trajectory for the Radiation was considerably different than suggested by raw diversity time-series. Our analyses suggest that a substantial portion of the increase recognized in raw diversity depictions for the last three Ordovician epochs (the Llandeilian, Caradocian, and Ashgillian) is a consequence of increased sample size of the preserved and catalogued fossil record. We also use biometric data for a global sample of Ordovician trilobites, along with methods of measuring morphological diversity that are not biased by sample size, to show that morphological diversification in this major clade had leveled off by the Llanvirnian. The discordance between raw diversity depictions and more robust taxonomic and morphological diversity metrics suggests that sampling effects may strongly influence our perception of biodiversity trends throughout the Phanerozoic.

  10. Formalization, annotation and analysis of diverse drug and probe screening assay datasets using the BioAssay Ontology (BAO.

    Directory of Open Access Journals (Sweden)

    Uma D Vempati

    Full Text Available Huge amounts of high-throughput screening (HTS data for probe and drug development projects are being generated in the pharmaceutical industry and more recently in the public sector. The resulting experimental datasets are increasingly being disseminated via publically accessible repositories. However, existing repositories lack sufficient metadata to describe the experiments and are often difficult to navigate by non-experts. The lack of standardized descriptions and semantics of biological assays and screening results hinder targeted data retrieval, integration, aggregation, and analyses across different HTS datasets, for example to infer mechanisms of action of small molecule perturbagens. To address these limitations, we created the BioAssay Ontology (BAO. BAO has been developed with a focus on data integration and analysis enabling the classification of assays and screening results by concepts that relate to format, assay design, technology, target, and endpoint. Previously, we reported on the higher-level design of BAO and on the semantic querying capabilities offered by the ontology-indexed triple store of HTS data. Here, we report on our detailed design, annotation pipeline, substantially enlarged annotation knowledgebase, and analysis results. We used BAO to annotate assays from the largest public HTS data repository, PubChem, and demonstrate its utility to categorize and analyze diverse HTS results from numerous experiments. BAO is publically available from the NCBO BioPortal at http://bioportal.bioontology.org/ontologies/1533. BAO provides controlled terminology and uniform scope to report probe and drug discovery screening assays and results. BAO leverages description logic to formalize the domain knowledge and facilitate the semantic integration with diverse other resources. As a consequence, BAO offers the potential to infer new knowledge from a corpus of assay results, for example molecular mechanisms of action of perturbagens.

  11. Sensitivity of routine coagulation assays to direct oral anticoagulants: patient samples versus commercial drug-specific calibrators.

    Science.gov (United States)

    Lim, Ming Sheng; Chapman, Kent; Swanepoel, Priscilla; Enjeti, Anoop K

    2016-12-01

    Most studies on the sensitivities of coagulation assays to direct oral anticoagulants (DOACs) are based on normal plasma spiked with anticoagulant in the laboratory. Recent studies have shown that reagent sensitivity varies significantly depending on whether spiked or patient samples are used. The aim of this study was to compare the sensitivities of routine coagulation assays in patient samples and commercial drug specific calibrators using commonly used activated partial thromboplastin time (APTT) and prothrombin time (PT) reagents (i.e., Actin FS and Neoplastine CI Plus for APTT and PT, respectively) in Australian laboratories. Samples collected at Pathology North Hunter (PN-H) for dabigatran (n=39), rivaroxaban, (n=56) or apixaban levels (n=22) between February 2013 and November 2015 were analysed and compared to two different commercial drug specific calibrators from different manufacturers for each DOAC. Our results show that dabigatran (Hyphen and Technoclone) and rivaroxaban (Stago) calibrators tend to overestimate the APTT but are similar to patient samples for PT. A cut-off DOAC level of 50 ng/mL based on results from patient samples within the laboratory can be used as the lower limit which will result in prolongation of APTT for dabigatran (sensitivity 96%, n=25) and PT for rivaroxaban (sensitivity 97%, n=29), respectively. Individual laboratories should be familiar with the sensitivity of their coagulation reagents to different DOACs including differences between patient samples versus different commercial drug specific calibrators. Copyright © 2016 Royal College of Pathologists of Australasia. All rights reserved.

  12. Albumin-based or albumin-linked calibrators cause a positive bias in serum proteins assayed by the biuret method.

    Science.gov (United States)

    Chromý, Vratislav; Sváchová, Lenka; Novosád, Lukás; Jarkovský, Jirí; Sedlák, Pavel; Horák, Petr; Dobrovolná, Hana; Hlavácová, Barbora

    2009-01-01

    Assay of total serum protein by the biuret method calibrated with albumin standards according to the reference method provides results with a positive bias approximately 3%-5% exceeding the total error of 3.4% allowable for total protein in serum analysis made by analysers using two-part reagents and short-term procedures. We used two types of two-part biuret reagents utilised in a short-term measurement in analysers with albumin or serum calibrators, in which protein was attested by the Kjeldahl method. Tests with potentially interfering substances proved that serum blanking used in a short-term biuret procedure is not capable of sufficiently eliminating effects of serum interferents. A short-term blanking is evidently capable of suppressing only an absorbance caused by serum-present coloured and turbid interferents, but its capacity to transform them (oxidise, hydrolyse, saponify, etc.) to some other not-interfering substances is very low compared with a long-term blanking. Lipids and bilirubin are responsible for significant positive bias of total protein in normal serum samples (approximately 3%) and even a greater positive offset in lipaemic and icteric sera (approximately 5%). We verified that interference tests based on a normal serum spiked with endogenous lipids and bilirubin give quite false and misleading results in the biuret reaction. A pure albumin, not depending on its bovine/human origin, gives absorbance responding only to its copper complexes with protein with a biuret regent, while its absorbance with a serum also includes the absorbance of interferents present in serum. The simplest way to improve current short-term biuret procedures is the use of a human serum calibrator with total protein attested by the Kjeldahl method. A serum calibrator, behaving analogously to serum samples, compensates for a positive bias in most normal sera. Reagents with a greater concentration of active biuret components (copper and alkali, reference method included

  13. Metrological tests of a 200 L calibration source for HPGE detector systems for assay of radioactive waste drums.

    Science.gov (United States)

    Boshkova, T; Mitev, K

    2016-03-01

    In this work we present test procedures, approval criteria and results from two metrological inspections of a certified large volume (152)Eu source (drum about 200L) intended for calibration of HPGe gamma assay systems used for activity measurement of radioactive waste drums. The aim of the inspections was to prove the stability of the calibration source during its working life. The large volume source was designed and produced in 2007. It consists of 448 identical sealed radioactive sources (modules) apportioned in 32 transparent plastic tubes which were placed in a wooden matrix which filled the drum. During the inspections the modules were subjected to tests for verification of their certified characteristics. The results show a perfect compliance with the NIST basic guidelines for the properties of a radioactive certified reference material (CRM) and demonstrate the stability of the large volume CRM-drum after 7 years of operation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Low agreement between fresh and frozen-thawed platelet-rich plasma in the calibrated automated thrombogram assay.

    Science.gov (United States)

    Ljungkvist, M; Lövdahl, S; Zetterberg, E; Berntorp, E

    2017-05-01

    Thrombin generation tests (TGTs) are considered to give more detailed information of the overall coagulation capability of a patient than clotting-based routine assays. The TGT thrombin generation assay-calibrated automated thrombogram (TGA-CAT) uses both platelet-poor plasma (PPP) and platelet-rich plasma (PRP). Assessing PRP gives more physiological test conditions and is of great interest considering the important role platelets play in haemostasis. However, PRP needs to be assessed close after blood draw/preparation as freezing fragments the platelets. In several previous publications, the utility of frozen-thawed PRP (ft-PRP) has been promoted, and in one article, no significant difference between fresh PRP (f-PRP) and ft-PRP was reported. The aim of our study was to investigate the level of agreement between f-PRP and ft-PRP to further validate these results. Our test population contained 41 persons with haemophilia and 45 healthy subjects. We used the TGA-CAT method with a set-up according to the manufacturer of the method. The measurements showed a poor level of agreement between f-PRP and ft-PRP and differences were not systematic. Fresh and ft-PRP cannot be assumed to show equal results in the TGA-CAT assay. © 2017 John Wiley & Sons Ltd.

  15. Extracellular Enzyme Activity assay as indicator of soil microbial functional diversity and activity

    DEFF Research Database (Denmark)

    Hendriksen, Niels Bohse; Winding, Anne

    2012-01-01

    Extracellular Enzyme Activity assay as indicator of soil microbial functional diversity and activity Niels Bohse Hendriksen, Anne Winding. Department of Environmental Science, Aarhus University, 4000 Roskilde, Denmark Soil enzymes originate from a variety of organisms, notably fungi and bacteria...... and especially hydrolytic extracellular enzymes are of pivotal importance for decomposition of organic substrates and biogeochemical cycling. Their activity reflects the functional diversity and activity of the microorganisms involved in decomposition processes which are essential processes for soil functioning......, experimental conditions of extraction of enzymes from soils, buffer and pH, substrate concentration, temperature and the necessary controls were optimized and standardized. This has resulted in an optimized standard operating procedure of EEA, which are being tested as an indicator of soil functional diversity...

  16. A High-resolution Typing Assay for Uropathogenic Escherichia coli Based on Fimbrial Diversity.

    Science.gov (United States)

    Ren, Yi; Palusiak, Agata; Wang, Wei; Wang, Yi; Li, Xiao; Wei, Huiting; Kong, Qingke; Rozalski, Antoni; Yao, Zhi; Wang, Quan

    2016-01-01

    Urinary tract infections (UTIs) are one of the most common bacterial infections in humans, causing cystitis, pyelonephritis, and renal failure. Uropathogenic Escherichia coli (UPEC) is the leading cause of UTIs. Accurate and rapid discrimination of UPEC lineages is useful for epidemiological surveillance. Fimbriae are necessary for the adherence of UPEC strains to host uroepithelia, and seem to be abundant and diverse in UPEC strains. By analyzing all the possible fimbrial operons in UPEC strains, we found that closely related strains had similar types of chaperone-usher fimbriae, and the diversity of fimbrial genes was higher than that of multilocus sequence typing (MLST) genes. A typing assay based on the polymorphism of four gene sequences (three fimbrial genes and one housekeeping gene) and the diversity of fimbriae present was developed. By comparison with the MLST, whole-genome sequence (WGS) and fumC/fimH typing methods, this was shown to be accurate and have high resolution, and it was also relatively inexpensive and easy to perform. The assay can supply more discriminatory information for UPEC lineages, and have the potential to be applied in epidemiological surveillance of UPEC isolates.

  17. Genetic diversity and relationships in mulberry (genus Morus as revealed by RAPD and ISSR marker assays

    Directory of Open Access Journals (Sweden)

    Thangavelu K

    2004-01-01

    Full Text Available Abstract Background The genus Morus, known as mulberry, is a dioecious and cross-pollinating plant that is the sole food for the domesticated silkworm, Bombyx mori. Traditional methods using morphological traits for classification are largely unsuccessful in establishing the diversity and relationships among different mulberry species because of environmental influence on traits of interest. As a more robust alternative, PCR based marker assays including RAPD and ISSR were employed to study the genetic diversity and interrelationships among twelve domesticated and three wild mulberry species. Results RAPD analysis using 19 random primers generated 128 discrete markers ranging from 500–3000 bp in size. One-hundred-nineteen of these were polymorphic (92%, with an average of 6.26 markers per primer. Among these were a few putative species-specific amplification products which could be useful for germplasm classification and introgression studies. The ISSR analysis employed six anchored primers, 4 of which generated 93 polymorphic markers with an average of 23.25 markers per primer. Cluster analysis of RAPD and ISSR data using the WINBOOT package to calculate the Dice coefficient resulted into two clusters, one comprising polyploid wild species and the other with domesticated (mostly diploid species. Conclusion These results suggest that RAPD and ISSR markers are useful for mulberry genetic diversity analysis and germplasm characterization, and that putative species-specific markers may be obtained which can be converted to SCARs after further studies.

  18. Quantification of coagulation factor XIII activity by a thio-NADH based assay using factor XIII immuno-depleted plasma as a diluent for calibration.

    Science.gov (United States)

    Kappel, Andreas; Stephan, Sina; Christ, Gerlinde; Pechmann, Lena; Duwe, Christa; Fischer, Bodo; Hahn, Martin; Althaus, Harald; Ehm, Matthias; Schwarz, Herbert; Vitzthum, Frank

    2010-12-01

    Accurate determination of factor XIII (FXIII) activity is crucial for replacement therapy. FXIII activity is typically determined using a coupled enzymatic reaction that measures nicotinamide adenine dinucleotide hydride (NADH) consumption at 340 nm. Here, we describe the development of a prototype for a novel FXIII activity assay for detection at 405 nm by replacing NADH with thio-NADH, and the application of FXIII immuno-depleted plasma as a diluent for calibration. Performance data show up to two-fold lower susceptibility of the prototype assay to interferences from hemolyzed, icteric, and lipemic samples when compared to a NADH assay format. In addition, the use of FXIII immuno-depleted plasma as diluent for calibration improved recovery almost two-fold in the lower measurement range. The novel prototype assay correlates well with a conventional assay (r=0.98, y=0.99·x+2.17% FXIII, n=173). The described prototype assay has the potential to (a) increase trueness of measurement of low levels of FXIII, (b) improve robustness due to reduction from interferences, and (c) can be used on a broad range of coagulation instruments due to its detection at 405 nm.

  19. Extracellular enzyme activity assay as indicator of soil microbial functional diversity and activity

    DEFF Research Database (Denmark)

    Hendriksen, Niels Bohse; Winding, Anne

    2012-01-01

    Extracellular enzyme activity assay as indicator of soil microbial functional diversity and activity Niels Bohse Hendriksen, Anne Winding. Department of Environmental Science, Aarhus University, 4000 Roskilde, Denmark Soils provide numerous essential ecosystem services such as carbon cycling......, recycling of nutrients and waste, soil remediation, plant growth support and regulation of above ground biodiversity, resilience, and soil suppressiveness. As such, soil ecosystem services are beneficial and vital for human life and at the same time threatened by anthropogenic activities. Increasing...... of soil microbial functions is still needed. In soil, enzymes originate from a variety of organisms, notably fungi and bacteria and especially hydrolytic extracellular enzymes are of pivotal importance for decomposition of organic substrates and biogeochemical cycling. Their activity will reflect...

  20. Field calibration of blowfly-derived DNA against traditional methods for assessing mammal diversity in tropical forests.

    Science.gov (United States)

    Lee, Ping-Shin; Gan, Han Ming; Clements, Gopalasamy Reuben; Wilson, John-James

    2016-11-01

    Mammal diversity assessments based on DNA derived from invertebrates have been suggested as alternatives to assessments based on traditional methods; however, no study has field-tested both approaches simultaneously. In Peninsular Malaysia, we calibrated the performance of mammal DNA derived from blowflies (Diptera: Calliphoridae) against traditional methods used to detect species. We first compared five methods (cage trapping, mist netting, hair trapping, scat collection, and blowfly-derived DNA) in a forest reserve with no recent reports of megafauna. Blowfly-derived DNA and mist netting detected the joint highest number of species (n = 6). Only one species was detected by multiple methods. Compared to the other methods, blowfly-derived DNA detected both volant and non-volant species. In another forest reserve, rich in megafauna, we calibrated blowfly-derived DNA against camera traps. Blowfly-derived DNA detected more species (n = 11) than camera traps (n = 9), with only one species detected by both methods. The rarefaction curve indicated that blowfly-derived DNA would continue to detect more species with greater sampling effort. With further calibration, blowfly-derived DNA may join the list of traditional field methods. Areas for further investigation include blowfly feeding and dispersal biology, primer biases, and the assembly of a comprehensive and taxonomically-consistent DNA barcode reference library.

  1. Selecting the correct weighting factors for linear and quadratic calibration curves with least-squares regression algorithm in bioanalytical LC-MS/MS assays and impacts of using incorrect weighting factors on curve stability, data quality, and assay performance.

    Science.gov (United States)

    Gu, Huidong; Liu, Guowen; Wang, Jian; Aubry, Anne-Françoise; Arnold, Mark E

    2014-09-16

    A simple procedure for selecting the correct weighting factors for linear and quadratic calibration curves with least-squares regression algorithm in bioanalytical LC-MS/MS assays is reported. The correct weighting factor is determined by the relationship between the standard deviation of instrument responses (σ) and the concentrations (x). The weighting factor of 1, 1/x, or 1/x(2) should be selected if, over the entire concentration range, σ is a constant, σ(2) is proportional to x, or σ is proportional to x, respectively. For the first time, we demonstrated with detailed scientific reasoning, solid historical data, and convincing justification that 1/x(2) should always be used as the weighting factor for all bioanalytical LC-MS/MS assays. The impacts of using incorrect weighting factors on curve stability, data quality, and assay performance were thoroughly investigated. It was found that the most stable curve could be obtained when the correct weighting factor was used, whereas other curves using incorrect weighting factors were unstable. It was also found that there was a very insignificant impact on the concentrations reported with calibration curves using incorrect weighting factors as the concentrations were always reported with the passing curves which actually overlapped with or were very close to the curves using the correct weighting factor. However, the use of incorrect weighting factors did impact the assay performance significantly. Finally, the difference between the weighting factors of 1/x(2) and 1/y(2) was discussed. All of the findings can be generalized and applied into other quantitative analysis techniques using calibration curves with weighted least-squares regression algorithm.

  2. A line fiducial method for geometric calibration of cone-beam CT systems with diverse scan trajectories.

    Science.gov (United States)

    Jacobson, Matthew W; Ketcha, Michael Daniel; Capostagno, Sarah; Martin, Alexander; Uneri, Ali; Goerres, Joseph; De Silva, Tharindu; Reaungamornrat, Sureerat; Han, Runze; Manbachi, Amir; Stayman, Joseph Webster; Vogt, Sebastian; Kleinszig, Gerhard; Siewerdsen, Jeffrey H

    2017-11-08

    Modern cone-beam CT systems, especially C-arms, are capable of diverse source-detector orbits. However, geometric calibration of these systems using conventional configurations of spherical fiducials (BBs) may be challenged for novel source-detector orbits and system geometries. In part, this is because the BB configurations are designed with careful forethought regarding the intended orbit so that BB marker projections do not overlap in projection views. Examples include helical arrangements of BBs (Rougee et al Proc. SPIE 1897 161-9) such that markers do not overlap in projections acquired from a circular orbit and circular arrangements of BBs (Cho et al Med Phys 32 968-83). As a more general alternative, this work proposes a calibration method based on an array of line-shaped, radio-opaque wire segments. With this method, geometric parameter estimation is accomplished by relating the 3D line equations representing the wires to the 2D line equations of their projections. The use of line fiducials simplifies many challenges with fiducial recognition and extraction in an orbit-independent manner. For example, their projections can overlap only mildly, for any gantry pose, as long as the wires are mutually non-coplanar in 3D. The method was tested in application to circular and non-circular trajectories in simulation and in real orbits executed using a mobile C-arm prototype for cone-beam CT. Results indicated high calibration accuracy, as measured by forward and backprojection/triangulation error metrics. Triangulation errors on the order of microns and backprojected ray deviations uniformly less than 0.2 mm were observed in both real and simulated orbits. Mean forward projection errors less than 0.1 mm were observed in a comprehensive sweep of different C-arm gantry angulations. Finally, successful integration of the method into a CT imaging chain was demonstrated in head phantom scans. © 2017 Institute of Physics and Engineering in Medicine.

  3. Interpreting sperm DNA damage in a diverse range of mammalian sperm by means of the two-tailed comet assay

    Directory of Open Access Journals (Sweden)

    Elva I eCortes-Gutierrez

    2014-11-01

    Full Text Available Sperm DNA damage is associated with fertilization failure, impaired pre-and post- embryo implantation and poor pregnancy outcome. A series of methodologies to assess DNA damage in spermatozoa have been developed but most are unable to differentiate between single-stranded DNA breaks (SSBs and double-stranded DNA breaks (DSBs on the same sperm cell. The two-dimensional Two-Tailed Comet assay (TT-comet protocol highlighted in this review overcomes this limitation and emphasizes the importance in accounting for difference in sperm protamine composition at a species-specific level for the appropriate preparation of the assay. The TT-comet is a modification of the original comet assay that uses a two dimensional electrophoresis to allow for the simultaneous evaluation of relatively high numbers of DSBs and SSBs in mammalian spermatozoa. Here we have compiled a retrospective overview of how the TT-comet assay has been used to investigate the structure and function of sperm DNA across a diverse range of mammalian species (eutheria, metatheria and prototheria. When conducted as part of the TT-comet assay, we discuss how (a the alkaline comet single assay has been used to help understand the constitutive and transient changes in DNA structure associated with chromatin packing, (b the capacity of the TT-comet to differentiate between the presence of SSBs and DSBs (c and the possible implications of SSBs or DSBs for the assessment of infertility.

  4. Electroluminescent TCC, C3dg and fB/Bb epitope assays for profiling complement cascade activation in vitro using an activated complement serum calibration standard.

    Science.gov (United States)

    van Vuuren, B Jansen; Bergseth, G; Mollnes, T E; Shaw, A M

    2014-01-15

    Electroluminescent assays for epitopes on the complement components C3dg, terminal complement complex (TCC) and factor B/Bb (fB/Bb) have been developed with capture and detection antibodies to produce detection limits C3dg=91±9ng/mL, TCC=3±0.1ng/mL and fB=55.7±0.1ng/mL. The assay performance was assessed against a series of zymosan and heat aggregated IgG (HAIgG) in vitro activations of complement using a calibrated activated complement serum (ACS) as calibration standard. The ACS standard was stable within 20% accuracy over a 6-month period with freeze-thaw cycles as required. Differential activation of the complement cascade was observed for TCC showing a pseudo-first order formation half-life of 3.5h after activation with zymosan. The C3dg activation fragment indicates a 10% total activation for both activation agents. The kinetic-epitope analysis for fB indicates that the capture epitope is on the fB/Bb protein fragment which can then become covered by the formation of C3bBb or C3bBbP complexes during the time course of the cascade. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Novel P450nor Gene Detection Assay Used To Characterize the Prevalence and Diversity of Soil Fungal Denitrifiers.

    Science.gov (United States)

    Novinscak, Amy; Goyer, Claudia; Zebarth, Bernie J; Burton, David L; Chantigny, Martin H; Filion, Martin

    2016-08-01

    Denitrifying fungi produce nitrous oxide (N2O), a potent greenhouse gas, as they generally lack the ability to convert N2O to dinitrogen. Contrary to the case for bacterial denitrifiers, the prevalence and diversity of denitrifying fungi found in the environment are not well characterized. In this study, denitrifying fungi were isolated from various soil ecosystems, and novel PCR primers targeting the P450nor gene, encoding the enzyme responsible for the conversion of nitric oxide to N2O, were developed, validated, and used to study the diversity of cultivable fungal denitrifiers. This PCR assay was also used to detect P450nor genes directly from environmental soil samples. Fungal denitrification capabilities were further validated using an N2O gas detection assay and a PCR assay targeting the nirK gene. A collection of 492 facultative anaerobic fungi was isolated from 15 soil ecosystems and taxonomically identified by sequencing the internal transcribed spacer sequence. Twenty-seven fungal denitrifiers belonging to 10 genera had the P450nor and the nirK genes and produced N2O from nitrite. N2O production is reported in strains not commonly known as denitrifiers, such as Byssochlamys nivea, Volutella ciliata, Chloridium spp., and Trichocladium spp. The prevalence of fungal denitrifiers did not follow a soil ecosystem distribution; however, a higher diversity was observed in compost and agricultural soils. The phylogenetic trees constructed using partial P450nor and nirK gene sequences revealed that both genes clustered taxonomically closely related strains together. A PCR assay targeting the P450nor gene involved in fungal denitrification was developed and validated. The newly developed P450nor primers were used on fungal DNA extracted from a collection of fungi isolated from various soil environments and on DNA directly extracted from soil. The results indicated that approximatively 25% of all isolated fungi possessed this gene and were able to convert nitrite to

  6. Sequence diversity in the glycoprotein B gene complicates real-time PCR assays for detection and quantification of cytomegalovirus.

    Science.gov (United States)

    Nye, Melinda B; Leman, Adam R; Meyer, Michelle E; Menegus, Marilyn A; Rothberg, Paul G

    2005-10-01

    Real-time quantitative PCR systems (Q-PCR) for the rapid detection and quantification of microorganisms in clinical specimens employ oligodeoxyribonucleotide primers and probes for specificity, which makes them vulnerable to false negatives caused by sequence diversity in the template. Schaade et al. (J. Clin. Microbiol. 39:3809, 2001) reported a sequence variant (C630T) in the cytomegalovirus (CMV) glycoprotein B (gB) gene that, although detectable in their Q-PCR assay, could not be accurately quantified. In an effort to evaluate the impact of CMV sequence variants in our patient population by use of a similar Q-PCR assay, we surveyed 54 isolates of CMV, each from a different patient. We detected evidence for the C630T variant in 4 of 54 (7.4%) patients. Furthermore, isolates from two additional patients were completely negative in the test. Sequencing of these false-negative isolates revealed multiple mutations within the probe hybridization sites. A Q-PCR that targeted the CMV polymerase gene instead of gB detected all 54 isolates. We suggest that Q-PCR assays for viral load be rigorously tested on large panels of viral isolates to assess the impact of sequence diversity on detection as well as quantification.

  7. Internal calibration Förster resonance energy transfer assay: a real-time approach for determining protease kinetics.

    Science.gov (United States)

    Jiang, Ling; Liu, Yan; Song, Yang; Saavedra, Amanda N; Pan, Songqin; Xiang, Wensheng; Liao, Jiayu

    2013-04-08

    Förster resonance energy transfer (FRET) technology has been widely used in biological and biomedical research. This powerful tool can elucidate protein interactions in either a dynamic or steady state. We recently developed a series of FRET-based technologies to determine protein interaction dissociation constant and for use in high-throughput screening assays of SUMOylation. SUMO (small ubiquitin-like modifier) is conjugated to substrates through an enzymatic cascade. This important posttranslational protein modification is critical for multiple biological processes. Sentrin/SUMO-specific proteases (SENPs) act as endopeptidases to process the pre-SUMO or as isopeptidases to deconjugate SUMO from its substrate. Here, we describe a novel quantitative FRET-based protease assay for determining the kinetics of SENP1. Our strategy is based on the quantitative analysis and differentiation of fluorescent emission signals at the FRET acceptor emission wavelengths. Those fluorescent emission signals consist of three components: the FRET signal and the fluorescent emissions of donor (CyPet) and acceptor (YPet). Unlike our previous method in which donor and acceptor direct emissions were excluded by standard curves, the three fluorescent emissions were determined quantitatively during the SENP digestion process from onesample. New mathematical algorithms were developed to determine digested substrate concentrations directly from the FRET signal and donor/acceptor direct emissions. The kinetic parameters, kcat, KM, and catalytic efficiency (kcat/KM) of SENP1 catalytic domain for pre-SUMO1/2/3 were derived. Importantly, the general principles of this new quantitative methodology of FRET-based protease kinetic determinations can be applied to other proteases in a robust and systems biology approach.

  8. Internal Calibration Förster Resonance Energy Transfer Assay: A Real-Time Approach for Determining Protease Kinetics

    Science.gov (United States)

    Jiang, Ling; Liu, Yan; Song, Yang; Saavedra, Amanda N.; Pan, Songqin; Xiang, Wensheng; Liao, Jiayu

    2013-01-01

    Förster resonance energy transfer (FRET) technology has been widely used in biological and biomedical research. This powerful tool can elucidate protein interactions in either a dynamic or steady state. We recently developed a series of FRET-based technologies to determine protein interaction dissociation constant and for use in high-throughput screening assays of SUMOylation. SUMO (small ubiquitin-like modifier) is conjugated to substrates through an enzymatic cascade. This important posttranslational protein modification is critical for multiple biological processes. Sentrin/SUMO-specific proteases (SENPs) act as endopeptidases to process the pre-SUMO or as isopeptidases to deconjugate SUMO from its substrate. Here, we describe a novel quantitative FRET-based protease assay for determining the kinetics of SENP1. Our strategy is based on the quantitative analysis and differentiation of fluorescent emission signals at the FRET acceptor emission wavelengths. Those fluorescent emission signals consist of three components: the FRET signal and the fluorescent emissions of donor (CyPet) and acceptor (YPet). Unlike our previous method in which donor and acceptor direct emissions were excluded by standard curves, the three fluorescent emissions were determined quantitatively during the SENP digestion process from onesample. New mathematical algorithms were developed to determine digested substrate concentrations directly from the FRET signal and donor/acceptor direct emissions. The kinetic parameters, kcat, KM, and catalytic efficiency (kcat/KM) of SENP1 catalytic domain for pre-SUMO1/2/3 were derived. Importantly, the general principles of this new quantitative methodology of FRET-based protease kinetic determinations can be applied to other proteases in a robust and systems biology approach. PMID:23567524

  9. A multilocus assay reveals high nucleotide diversity and limited differentiation among Scandinavian willow grouse (Lagopus lagopus

    Directory of Open Access Journals (Sweden)

    Quintela Maria

    2008-12-01

    Full Text Available Abstract Background There is so far very little data on autosomal nucleotide diversity in birds, except for data from the domesticated chicken and some passerines species. Estimates of nucleotide diversity reported so far in birds have been high (~10-3 and a likely explanation for this is the generally higher effective population sizes compared to mammals. In this study, the level of nucleotide diversity has been examined in the willow grouse, a non-domesticated bird species from the order Galliformes, which also holds the chicken. The willow grouse (Lagopus lagopus has an almost circumpolar distribution but is absent from Greenland and the north Atlantic islands. It primarily inhabits tundra, forest edge habitats and sub-alpine vegetation. Willow grouse are hunted throughout its range, and regionally it is a game bird of great cultural and economical importance. Results We sequenced 18 autosomal protein coding loci from approximately 15–18 individuals per population. We found a total of 127 SNP's, which corresponds to 1 SNP every 51 bp. 26 SNP's were amino acid replacement substitutions. Total nucleotide diversity (πt was between 1.30 × 10-4 and 7.66 × 10-3 (average πt = 2.72 × 10-3 ± 2.06 × 10-3 and silent nucleotide diversity varied between 4.20 × 10-4and 2.76 × 10-2 (average πS = 9.22 × 10-3 ± 7.43 × 10-4. The synonymous diversity is approximately 20 times higher than in humans and two times higher than in chicken. Non-synonymous diversity was on average 18 times lower than the synonymous diversity and varied between 0 and 4.90 × 10-3 (average πa = 5.08 × 10-4 ± 7.43 × 103, which suggest that purifying selection is strong in these genes. FST values based on synonymous SNP's varied between -5.60 × 10-4 and 0.20 among loci and revealed low levels of differentiation among the four localities, with an overall value of FST = 0.03 (95% CI: 0.006 – 0.057 over 60 unlinked loci. Non-synonymous SNP's gave similar results. Low

  10. Interpreting sperm DNA damage in a diverse range of mammalian sperm by means of the two-tailed comet assay.

    Science.gov (United States)

    Cortés-Gutiérrez, Elva I; López-Fernández, Carmen; Fernández, José Luis; Dávila-Rodríguez, Martha I; Johnston, Stephen D; Gosálvez, Jaime

    2014-01-01

    the simultaneous evaluation of DSBs and SSBs in mammalian spermatozoa. Here we have compiled a retrospective overview of how the TT-comet assay has been used to investigate the structure and function of sperm DNA across a diverse range of mammalian species (eutheria, metatheria, and prototheria). When conducted as part of the TT-comet assay, we illustrate (a) how the alkaline comet single assay has been used to help understand the constitutive and transient changes in DNA structure associated with chromatin packing, (b) the capacity of the TT-comet to differentiate between the presence of SSBs and DSBs (c) and the possible implications of SSBs or DSBs for the assessment of infertility.

  11. Interpreting sperm DNA damage in a diverse range of mammalian sperm by means of the two-tailed comet assay

    Science.gov (United States)

    Cortés-Gutiérrez, Elva I.; López-Fernández, Carmen; Fernández, José Luis; Dávila-Rodríguez, Martha I.; Johnston, Stephen D.; Gosálvez, Jaime

    2014-01-01

    allow for the simultaneous evaluation of DSBs and SSBs in mammalian spermatozoa. Here we have compiled a retrospective overview of how the TT-comet assay has been used to investigate the structure and function of sperm DNA across a diverse range of mammalian species (eutheria, metatheria, and prototheria). When conducted as part of the TT-comet assay, we illustrate (a) how the alkaline comet single assay has been used to help understand the constitutive and transient changes in DNA structure associated with chromatin packing, (b) the capacity of the TT-comet to differentiate between the presence of SSBs and DSBs (c) and the possible implications of SSBs or DSBs for the assessment of infertility. PMID:25505901

  12. Application of a Human Fecal Marker Assay to Diverse Coastal Environments in California and Hawaii

    Science.gov (United States)

    Layton, B.; Boehm, A.

    2007-05-01

    Bacterial pollution at beaches is a growing problem of increasing national concern. Currently, the EPA uses Enterococcus as one measure of water quality for recreational contact. Recent work has suggested that rather than indicating anthropogenic pollution, enterococci may be indigenous to the environment. A human-specific gene marker for Enterococcus faecium (known as esp) was recently proposed as a molecular test for bacterial contamination of human origin. The present study applied the esp gene assay to a variety of coastal environments in California and Hawaii, including groundwater, sand, freshwater creeks, estuaries, and the surf zone. Results indicate that enterococci of human origin are present in many of these environments, suggesting that at least a portion of the bacterial pollution at these sites is a result of anthropogenic inputs rather than autochthonous microbial populations.

  13. A simple cell-based assay reveals that diverse neuropsychiatric risk genes converge on primary cilia.

    Directory of Open Access Journals (Sweden)

    Aaron Marley

    Full Text Available Human genetic studies are beginning to identify a large number of genes linked to neuropsychiatric disorders. It is increasingly evident that different genes contribute to risk for similar syndromes and, conversely, the same genes or even the same alleles cross over traditional diagnostic categories. A current challenge is to understand the cellular biology of identified risk genes. However, most genes associated with complex neuropsychiatric phenotypes are not related through a known biochemical pathway, and many have an entirely unknown cellular function. One possibility is that diverse disease-linked genes converge at a higher-level cellular structure. The synapse is already known to be one such convergence, and emerging evidence suggests the primary cilium as another. Because many genes associated with neuropsychiatric illness are expressed also outside the nervous system, as are cilia, we tested the hypothesis that such genes affect conserved features of the primary cilium. Using RNA interference to test 41 broadly expressed candidate genes associated with schizophrenia, bipolar affective disorder, autism spectrum disorder and intellectual disability, we found 20 candidates that reduce ciliation in NIH3T3 cells when knocked down, and three whose manipulation increases cilia length. Three of the candidate genes were previously implicated in cilia formation and, altogether, approximately half of the candidates tested produced a ciliary phenotype. Our results support the hypothesis that primary cilia indeed represent a conserved cellular structure at which the effects of diverse neuropsychiatric risk genes converge. More broadly, they suggest a relatively simple cell-based approach that may be useful for exploring the complex biological underpinnings of neuropsychiatric disease.

  14. Role of Assay Type in Determining Free 25-Hydroxyvitamin D Levels in Diverse Populations

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, Carrie M.; Jones, Kerry S.; Chun, Rene F.; Jacobs, Jon; Wang, Ying; Hewison, Martin; Adams, John S.; Swanson, Christine M.; Lee, Christine G.; Vanderschueren, Dirk; Pauwels, Steven; Prentice, Ann; Smith, Richard D.; Shi, Tujin; Gao, Yuqian; Zmuda, Joseph M.; Lapidus, Jodi; Cauley, Jane A.; Bouillon, Roger; Schoenmakers, Inez; Orwoll, Eric S.

    2016-04-28

    Serum 25-hydroxyvitamin D (25OHD) is the most frequently used marker of vitamin D status. Low 25OHD is associated with bone loss, fractures {Cauley, 2010 #1516;Ensrud, 2009 #1517}, and other adverse health outcomes {Theodoratou, 2014 #1518}. Most extra renal tissues only have access to free 25OHD, and free 25OHD concentration is thus a plausible biomarker of 25OHD availability and function {Johnsen, 2014 #1443;Chun, 2014 #1343}. Stronger associations with free or bioavailable 25OHD than with total 25OHD were reported for serum calcium, parathyroid hormone (PTH) {Bhan, 2012 #1124} and bone mineral density (BMD) {Powe, 2011 #1129}. These findings have led to the suggestion that free or bioavailable 25OHD may provide a more clinically relevant measure of tissue 25OHD availability and vitamin D status {Powe, 2013 #1369; Holick NEJM 2013 editorial}. The US Preventive Services Task Force (LeFevre 2015) recently pointed to the gap in research regarding bioavailable and free 25OHD and noted the possibility that these may be better markers of tissue 25OHD availability. Free 25OHD is conventionally calculated from the concentrations of total 25OHD, vitamin D binding protein (DBP) and albumin, with or without a factor accounting for DBP genotype-specific binding affinities {Bouillon, 1981 #1207;Chun, 2012 #1143; Powe, 2011 #1129;Johnsen, 2014 #1443}. DBP—or Group specific component (GC) {Hirschfeld, 1959 #1468}—polymorphisms (rs4588 and rs7041) give rise to three major polymorphic isoforms of DBP, GC-1F, GC-1S and GC-2, the frequencies of which differ globally, with GC-1F alleles more common in populations of African descent {Kambou, 1986 #1122}. Although DBP is a primary component of free and bioavailable 25OHD calculations, substantial variation in DBP between assays has been noted (Powe suggest to cite here previous publications as in previous version of this Ms). Using DBP measured by a monoclonal antibody Powe et al. {Powe, 2013 #1369} concluded that calculated free

  15. ARCHITECT HIV Combo Ag/Ab® and RealTime® HIV-1 assays detect diverse HIV strains in clinical specimens.

    Science.gov (United States)

    Rodgers, Mary A; Vallari, Ana S; Yamaguchi, Julie; Holzmayer, Vera; Harris, Barbara; Toure-Kane, Coumba; M'Boup, Souleymane; Badreddine, Samar; McArthur, Carole; Ndembi, Nicaise; Mbanya, Dora Ngum; Kaptué, Lazare; Cloherty, Gavin

    2017-12-12

    Periodic evaluation of the impact of viral diversity on diagnostic tests is critical to ensure current technologies are keeping pace with viral evolution. To determine whether HIV diversity impacts the ARCHITECT HIV Combo Ag/Ab (HIV Combo) or RealTime HIV-1 (RT) assays, a set of N=199 HIV clinical specimens from Cameroon, Senegal, Saudi Arabia, and Thailand were sequenced and tested in both assays. The panel included historical Group N and P specimens and a newly identified Group N specimen. These and specimens classified as H, U/URF, CRF01, 02, 06, 09, 11, 13, 18, 22, 37, and 43 were detected by both the RT assay (1.75-6.84 log copies/ml) and the HIV Combo assay (3.26-1121.96 sample to cutoff ratios). Sequence alignment identified 3 or fewer mismatches to the RT assay oligos in 82.4% of samples. Altogether, these data demonstrate the HIV Combo and RT assays detect diverse strains of HIV in clinical specimens.

  16. Enzyme assays

    OpenAIRE

    Bisswanger, Hans

    2014-01-01

    The essential requirements for enzyme assays are described and frequently occurring errors and pitfalls as well as their avoidance are discussed. The main factors, which must be considered for assaying enzymes, are temperature, pH, ionic strength and the proper concentrations of the essential components like substrates and enzymes. Standardization of these parameters would be desirable, but the diversity of the features of different enzymes prevents unification of assay conditions. Neverthele...

  17. ARCHITECT® HIV Ag/Ab Combo assay: correlation of HIV-1 p24 antigen sensitivity and RNA viral load using genetically diverse virus isolates.

    Science.gov (United States)

    Brennan, Catherine A; Yamaguchi, Julie; Vallari, Ana; Swanson, Priscilla; Hackett, John R

    2013-06-01

    HIV antigen/antibody (Ag/Ab) combination assays represent a significant advancement in assays used for diagnosing HIV infection based on their ability to detect acute and chronic infections. During acute HIV infection (AHI), detection depends on assay sensitivity for p24 Ag. To directly compare the Ag sensitivity of the ARCHITECT(®) HIV Ag/Ab Combo assay to RNA viral load using cell culture supernatants of virus isolates. HIV-1 isolates allow correlation in the total absence of an antibody response to infection and across genetically diverse HIV-1 group M strains. Thirty-five HIV-1 isolates comprising subtypes A-D, F and G, CRF01_AE, CRF02_AG, and unique recombinant forms were evaluated. Cell-free culture supernatant for each isolate was diluted to four levels and tested in the HIV Combo assay to determine a signal to cutoff ratio and the RealTime(®) HIV-1 assay to quantify RNA. The RNA copies/mL at the HIV Combo assay cutoff was determined. The median RNA copies/mL at the HIV Combo assay cutoff was 57,900 for individual virus isolates (range 26,440-102,400). A single plot of all the data gave a value of 58,500RNA copies/mL. An analysis of data published for acute HIV infection in human subjects gave a similar result; HIV Combo detected 97% of AHIs with RNA copies/mL > 30,700. Based on analysis of virus isolates, the ARCHITECT HIV Combo assay can detect p24 Ag when RNA is above approximately 58,000copies/mL. The correlation of viral load and Ag sensitivity was consistent across genetically diverse HIV-1 group M strains. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Calibrating snakehead diversity with DNA barcodes: expanding taxonomic coverage to enable identification of potential and established invasive species.

    Science.gov (United States)

    Serrao, Natasha R; Steinke, Dirk; Hanner, Robert H

    2014-01-01

    Detecting and documenting the occurrence of invasive species outside their native range requires tools to support their identification. This can be challenging for taxa with diverse life stages and/or problematic or unresolved morphological taxonomies. DNA barcoding provides a potent method for identifying invasive species, as it allows for species identification at all life stages, including fragmentary remains. It also provides an efficient interim taxonomic framework for quantifying cryptic genetic diversity by parsing barcode sequences into discontinuous haplogroup clusters (typical of reproductively isolated species) and labelling them with unique alphanumeric identifiers. Snakehead fishes are a diverse group of opportunistic predators endemic to Asia and Africa that may potentially pose significant threats as aquatic invasive species. At least three snakehead species (Channa argus, C. maculata, and C. marulius) are thought to have entered North America through the aquarium and live-food fish markets, and have established populations, yet their origins remain unclear. The objectives of this study were to assemble a library of DNA barcode sequences derived from expert identified reference specimens in order to determine the identity and aid invasion pathway analysis of the non-indigenous species found in North America using DNA barcodes. Sequences were obtained from 121 tissue samples representing 25 species and combined with public records from GenBank for a total of 36 putative species, which then partitioned into 49 discrete haplogroups. Multiple divergent clusters were observed within C. gachua, C. marulius, C. punctata and C. striata suggesting the potential presence of cryptic species diversity within these lineages. Our findings demonstrate that DNA barcoding is a valuable tool for species identification in challenging and under-studied taxonomic groups such as snakeheads, and provides a useful framework for inferring invasion pathway analysis.

  19. Calibrating snakehead diversity with DNA barcodes: expanding taxonomic coverage to enable identification of potential and established invasive species.

    Directory of Open Access Journals (Sweden)

    Natasha R Serrao

    Full Text Available Detecting and documenting the occurrence of invasive species outside their native range requires tools to support their identification. This can be challenging for taxa with diverse life stages and/or problematic or unresolved morphological taxonomies. DNA barcoding provides a potent method for identifying invasive species, as it allows for species identification at all life stages, including fragmentary remains. It also provides an efficient interim taxonomic framework for quantifying cryptic genetic diversity by parsing barcode sequences into discontinuous haplogroup clusters (typical of reproductively isolated species and labelling them with unique alphanumeric identifiers. Snakehead fishes are a diverse group of opportunistic predators endemic to Asia and Africa that may potentially pose significant threats as aquatic invasive species. At least three snakehead species (Channa argus, C. maculata, and C. marulius are thought to have entered North America through the aquarium and live-food fish markets, and have established populations, yet their origins remain unclear. The objectives of this study were to assemble a library of DNA barcode sequences derived from expert identified reference specimens in order to determine the identity and aid invasion pathway analysis of the non-indigenous species found in North America using DNA barcodes. Sequences were obtained from 121 tissue samples representing 25 species and combined with public records from GenBank for a total of 36 putative species, which then partitioned into 49 discrete haplogroups. Multiple divergent clusters were observed within C. gachua, C. marulius, C. punctata and C. striata suggesting the potential presence of cryptic species diversity within these lineages. Our findings demonstrate that DNA barcoding is a valuable tool for species identification in challenging and under-studied taxonomic groups such as snakeheads, and provides a useful framework for inferring invasion pathway

  20. Rover waste assay system

    Energy Technology Data Exchange (ETDEWEB)

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-11-01

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched {sup 235}U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for {sup 137}Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs.

  1. Chorioallantoic membrane assays have been based on diffusion control--problems arising with a diversity of mass transfers in egg white.

    Science.gov (United States)

    Hsieh, Chiu-Lan; Peng, Chiung-Chi; Lin, Li-Yun; Cheng, Yu-Ting; Chen, Kuan-Chou; Peng, Robert Y

    2009-01-01

    The chorioallantoic membrane (CAM) assays have been intensively used to determine angiogenesis and anti-angiogenesis of medicines. In view of bioactivity, this technique should be performed with kinetic control regime in chicken embryos. Whether the dosages ever used had satisfied this requirement, we explored by mathematical analysis. A diffusion-in-egg model was established to describe several medicinal diffusions in egg white that involved the instantaneous transient kinetic behavior, the diffusion of medicines in capping volume (the volume from the air sac to the interface of egg yolk). By reviewing the diffusion of various compounds including the cited and the experimentals in this work, we conclude that all the CAM assays ever cited were performed under diffusion control regime rather than kinetic control, which may bring forth deviations caused by a diversity of constitutes in egg white through various medicine-protein interactions.

  2. Diversity and distribution of marine Synechococcus: multiple gene phylogenies for consensus classification and development of qPCR assays for sensitive measurement of clades in the ocean

    Directory of Open Access Journals (Sweden)

    Nathan A Ahlgren

    2012-06-01

    Full Text Available Marine Synechococcus is a globally significant genus of cyanobacteria that is comprised of multiple genetic lineages or clades. These clades are thought to represent ecologically distinct units, or ecotypes. Because multiple clades often co-occur together in the oceans, Synechococcus are ideal microbes to explore how closely related bacterial taxa within the same functional guild of organisms coexist and partition marine habitats. Here we perform multi-locus sequencing of cultured strains to confirm the congruency of clade classifications between the 16S-23S rDNA internally transcribed spacer (ITS, 16S rDNA, narB, ntcA, and rpoC1, loci commonly used in Synechococcus diversity studies. We designed quantitative PCR (qPCR assays that target the ITS for ten Synechococcus clades, including four clades, XV, XVI, CRD1, and CRD2, not covered by previous assays employing other loci. Our new qPCR assays are very sensitive and specific, detecting as few as tens of cells per ml. Application of these qPCR assays to field samples from the northwest Atlantic showed clear shifts in Synechococcus community composition across a coastal to open ocean transect. Consistent with previous studies, clades I and IV dominated cold, coastal Synechococcus communities. Clades II and X were abundant at the two warmer, off-shore stations, and at all stations multiple Synechococcus clades co-occurred. qPCR assays developed here provide valuable tools to further explore the dynamics of microbial community structure and the mechanisms of co-existence.

  3. Investigation of miscellaneous hERG inhibition in large diverse compound collection using automated patch-clamp assay.

    Science.gov (United States)

    Yu, Hai-bo; Zou, Bei-yan; Wang, Xiao-liang; Li, Min

    2016-01-01

    hERG potassium channels display miscellaneous interactions with diverse chemical scaffolds. In this study we assessed the hERG inhibition in a large compound library of diverse chemical entities and provided data for better understanding of the mechanisms underlying promiscuity of hERG inhibition. Approximately 300 000 compounds contained in Molecular Library Small Molecular Repository (MLSMR) library were tested. Compound profiling was conducted on hERG-CHO cells using the automated patch-clamp platform-IonWorks Quattro(™). The compound library was tested at 1 and 10 μmol/L. IC50 values were predicted using a modified 4-parameter logistic model. Inhibitor hits were binned into three groups based on their potency: high (IC5010 μmol/L) with hit rates of 1.64%, 9.17% and 16.63%, respectively. Six physiochemical properties of each compound were acquired and calculated using ACD software to evaluate the correlation between hERG inhibition and the properties: hERG inhibition was positively correlative to the physiochemical properties ALogP, molecular weight and RTB, and negatively correlative to TPSA. Based on a large diverse compound collection, this study provides experimental evidence to understand the promiscuity of hERG inhibition. This study further demonstrates that hERG liability compounds tend to be more hydrophobic, high-molecular, flexible and polarizable.

  4. Interpreting sperm DNA damage in a diverse range of mammalian sperm by means of the two-tailed comet assay

    OpenAIRE

    Elva I eCortes-Gutierrez; Carmen eLopez-Fernandez; Jose Luis Fernandez; Martha I Davila-Rodriguez; Stephen eJohnston; Jaime eGosalvez

    2014-01-01

    Key Concepts The two-dimensional Two-Tailed Comet assay (TT-comet) protocol is a valuable technique to differentiate between single-stranded (SSBs) and double-stranded DNA breaks (DSBs) on the same sperm cell. Protein lysis inherent with the TT-comet protocol accounts for differences in sperm protamine composition at a species-specific level to produce reliable visualization of sperm DNA damage. Alkaline treatment may break the sugar–phosphate backbone in abasic sites or at sites wi...

  5. Investigating the Generalizability of the MultiFlow® DNA Damage Assay and Several Companion Machine Learning Models with a Set of 103 Diverse Test Chemicals.

    Science.gov (United States)

    Bryce, Steven M; Bernacki, Derek T; Smith-Roe, Stephanie L; Witt, Kristine L; Bemis, Jeffrey C; Dertinger, Stephen D

    2017-11-02

    The in vitro MultiFlow® DNA Damage assay multiplexes p53, γH2AX, phospho-histone H3, and polyploidization biomarkers into one flow cytometric analysis (Bryce et al., 2016). The work reported herein evaluated the generalizability of the method, as well as several data analytics strategies, to a range of chemical classes not studied previously. TK6 cells were exposed to each of 103 diverse chemicals, 86 of which were supplied by the National Toxicology Program (NTP) and selected based upon responses in genetic damage assays conducted under the Tox21 program. Exposures occurred for 24 h over a range of concentrations, and cell aliquots were removed at 4 and 24 h for analysis. Multiplexed response data were evaluated using 3 machine learning models designed to predict genotoxic mode of action based on data from a training set of 85 previously studied chemicals. Of 54 chemicals with sufficient information to make an a priori call on genotoxic potential, the prediction models' accuracies were 79.6% (random forest), 88.9% (logistic regression), and 90.7% (artificial neural network). A majority vote ensemble of the 3 models provided 92.6% accuracy. Forty-nine NTP chemicals were not adequately tested (maximum concentration did not approach assay's cytotoxicity limit) and/or had insufficient conventional genotoxicity data to allow their genotoxic potential to be defined. For these chemicals MultiFlow data will be useful in future research and hypothesis testing. Collectively, the results suggest the MultiFlow assay and associated data analysis strategies are broadly generalizable, demonstrating high predictability when applied to new chemicals and classes of compounds. Published by Oxford University Press on behalf of the Society of Toxicology 2017. This work is written by US Government employees and is in the public domain in the US.

  6. Site Calibration

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    This Site Calibration report is describing the results of a measured site calibration for a site in Denmark. The calibration is carried out by DTU Wind Energy in accordance with Ref.[3] and Ref.[4]. The measurement period is given. The site calibration is carried out before a power performance...... measurement on a given turbine to clarify the influence from the terrain on the ratio between the wind speed at the center of the turbine hub and at the met mast. The wind speed at the turbine is measured by a temporary mast placed at the foundation for the turbine. The site and measurement equipment...

  7. Calibration uncertainty

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Anglov, Thomas

    2002-01-01

    Methods recommended by the International Standardization Organisation and Eurachem are not satisfactory for the correct estimation of calibration uncertainty. A novel approach is introduced and tested on actual calibration data for the determination of Pb by ICP-AES. The improved calibration...... uncertainty was verified from independent measurements of the same sample by demonstrating statistical control of analytical results and the absence of bias. The proposed method takes into account uncertainties of the measurement, as well as of the amount of calibrant. It is applicable to all types...

  8. GPI Calibrations

    Science.gov (United States)

    Rantakyrö, Fredrik T.

    2017-09-01

    "The Gemini Planet Imager requires a large set of Calibrations. These can be split into two major sets, one set associated with each observation and one set related to biweekly calibrations. The observation set is to optimize the correction of miscroshifts in the IFU spectra and the latter set is for correction of detector and instrument cosmetics."

  9. Comparative genetic diversity of wild and hatchery-produced populations of tongue sole (Cynoglossus semilaevis) using multiplex PCR assays with polymorphic microsatellite markers.

    Science.gov (United States)

    An, H S; Kim, E-M; Kang, H W; Han, H S; Lee, J W; Park, J Y; Myeong, J I; An, C M

    2013-12-04

    The tongue sole, Cynoglossus semilaevis (Cynoglossidae), is one of the most economically important fishery resources in Korea. This study presents a preliminary investigation of the future viability of the complete aquaculture of tongue sole in Korea. Specifically, possible differences in genetic variability between wild populations of tongue sole from Korea and hatchery-produced populations of tongue sole from China were assessed using multiplex assays with 12 polymorphic nuclear microsatellite DNA loci. High levels of polymorphism were observed between the 2 populations. A total of 135 different alleles were found, varying from 5-15 alleles per locus, with some alleles being unique. These findings indicate a high level of genetic variability in both the wild and hatchery-produced populations. Although a considerable loss of rare alleles was observed in hatchery samples, there were no statistically significant reductions of heterozygosity or allelic diversity in the hatchery population compared to the wild population. Moreover, the inbreeding coefficient was very low (FIS = -0.010-0.052) for both populations. However, significant genetic heterogeneity was found between the 2 populations. These findings indicate that genetic drift has likely promoted differentiation between these 2 populations, and might have negative effects on the reproductive capacity of the stock, because genetic factors are important in the production of high quality seed for complete aquaculture. Therefore, aquaculture management should incorporate basic genetic principles into existing molecular monitoring protocols. The information compiled by this study is anticipated to provide a useful genetic basis for future complete culturing plans and management of C. semilaevis in fisheries.

  10. Accurate borehole probe calibration

    Energy Technology Data Exchange (ETDEWEB)

    Tchen, T.; Eisler, P. (CSIRO, Mount Waverley, Vic. (Australia). Division of Geomechanics)

    The In Situ Minerals Analysis Group in the CSIRO Division of Geomechanics has developed quantitative borehole logging techniques applicable to iron-ore and coal deposits. They are used currently to determine the formation density, either the iron-ore grades or the raw coal-ash contents, as appropriate, and the borehole diameter. The in-situ analyses depend on probe-calibration equations which were formulated by linear regression analysis that related the probe's spectral outputs with the required geological variable. Calibration equations consisting of a linear combination of first-order terms gave excellent assaying accuracy. The group achieved further improvements in assaying accuracy by developing a more generalised calibration model based on second-order terms and cross-product terms of the probe's spectral parameters. The logging data used for the statistical analysis were recorded in mine development boreholes at three Pilbara iron-ore mines and at a Queensland coal mine. Application of the generalised model, in place of the first-order model, resulted in a reduction of the root mean square (RMS) deviation between assays obtained in the laboratory and by logging, of about 15% relative for iron-ore grades and of about 8% relative for raw coal-ash content. The study also shows that the accuracy obtained using the conventional, non-spectrometric calibration model is inferior to that obtained by using either of the two spectrometric models, where the comparisons made are based on the same set of logging data. 8 refs., 6 figs., 3 tabs.

  11. Site calibration

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Georgieva Yankova, Ginka

    The report describes site calibration measurements carried out on a site in Denmark. The measurements are carried out in accordance to Ref. [1]. The site calibration is carried out before a power performance measurement on a given turbine to clarify the influence from the terrain on the ratio...... between the wind speed at the center of the turbine hub and at the met mast. The wind speed at the turbine is measured by a temporary mast placed at the foundation for the turbine. The site and measurement equipment is detailed described in [2]. The possible measurement sector for power performance...... according to [1] is also described in [2] and no results from the site calibration have shown any necessary exclusion from this sector. All parts of the sensors and the measurement system have been installed by DTU....

  12. The Effectiveness of Screening with Interferon-Gamma Release Assays in a University Health Care Setting with a Diverse Global Population

    Science.gov (United States)

    Birch, Samantha J.; Golbeck, Amanda L.

    2015-01-01

    Objective: This analysis examined the effectiveness of utilizing interferon-gamma release assay (IGRA) technology in a TB (TB) screening program at a university. Participants: Participants were 2299 students at a Montana university who had presented to the university health center for TB screening during 2012 and 2013. Methods: A retrospective…

  13. A near infrared spectroscopic assay for stalk soluble sugars, bagasse enzymatic saccharification and wall polymers in sweet sorghum.

    Science.gov (United States)

    Wu, Leiming; Li, Meng; Huang, Jiangfeng; Zhang, Hui; Zou, Weihua; Hu, Shiwei; Li, Ying; Fan, Chunfen; Zhang, Rui; Jing, Haichun; Peng, Liangcai; Feng, Shengqiu

    2015-02-01

    In this study, 123 sweet sorghum (Sorghum bicolor L.) accessions and 50 mutants were examined with diverse stalk soluble sugars, bagasse enzymatic saccharification and wall polymers, indicating the potential near infrared spectroscopy (NIRS) assay for those three important parameters. Using the calibration and validation sets and modified squares method, nine calibration optimal equations were generated with high determination coefficient on the calibration (R(2)) (0.81-0.99), cross-validation (R(2)cv) (0.77-0.98), and the ratio performance deviation (RPD) (2.07-7.45), which were at first time applied by single spectra for simultaneous assay of stalk soluble sugars, bagasse hydrolyzed sugars, and three major wall polymers in bioenergy sweet sorghum. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Survival assays using Caenorhabditis elegans.

    Science.gov (United States)

    Park, Hae-Eun H; Jung, Yoonji; Lee, Seung-Jae V

    2017-02-01

    Caenorhabditis elegans is an important model organism with many useful features, including rapid development and aging, easy cultivation, and genetic tractability. Survival assays using C. elegans are powerful methods for studying physiological processes. In this review, we describe diverse types of C. elegans survival assays and discuss the aims, uses, and advantages of specific assays. C. elegans survival assays have played key roles in identifying novel genetic factors that regulate many aspects of animal physiology, such as aging and lifespan, stress response, and immunity against pathogens. Because many genetic factors discovered using C. elegans are evolutionarily conserved, survival assays can provide insights into mechanisms underlying physiological processes in mammals, including humans.

  15. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina

    2016-05-02

    This poster presents the development, implementation, and operation of the Broadband Outdoor Radiometer Calibrations (BORCAL) Longwave (LW) system at the Southern Great Plains Radiometric Calibration Facility for the calibration of pyrgeometers that provide traceability to the World Infrared Standard Group.

  16. Applicability of generic assays based on liquid chromatography–electrospray mass spectrometry to study in vitro metabolism of 55 structurally diverse compounds

    Directory of Open Access Journals (Sweden)

    Timo Rousu

    2010-08-01

    Full Text Available Liquid chromatography-mass spectrometry (LC/MS with generic gradient elution for a large number of chemically different compounds is a common approach in drug development, used to acquire a large amount of data in a short time frame for drug candidates. The analysis with non-optimised parameters however may lead to a poor method performance for many compounds, and contains a risk of losing important information. Here, generic electrospray-time-of-flight (ESI-TOF MS methods in various pH conditions were tested for 55 chemically diverse compounds (10 acids, 25 bases, 17 neutrals and 3 amphoterics, aiming to find best analytical conditions for each compound, for studies of in vitro metabolic properties in liver preparations. The effect of eluent pH and elution gradient strength on chromatographic performance and electrospray MS ionisation efficiency were examined for each compound. The data are evaluated how well the best generic approach could cover the analysis of test compounds and how many compounds would still need completely different analytical conditions after that. Aqueous mobile phase consisting of 0.05% acetic acid and 5 mM ammonium acetate (pH 4.4 showed the best general suitability for the analyses, showing adequate performance for metabolite profiling for 41 out of 55 compounds either in positive or negative ion mode. In positive ion mode, the main limitation of performance in various pH conditions was generally not the lack of ionisation, but rather the poor chromatographic performance (inadequate retention or poor peak shape, suggesting that more emphasis should be put in finding conditions providing best chromatographic performance, rather than highest ionisation properties. However, a single generic approach for a large number of different compounds is not likely to produce good results for all compounds. Preferably, at least two or three different conditions are needed for the coverage of a larger number of structurally diverse

  17. Synthesis Polarimetry Calibration

    Science.gov (United States)

    Moellenbrock, George

    2017-10-01

    Synthesis instrumental polarization calibration fundamentals for both linear (ALMA) and circular (EVLA) feed bases are reviewed, with special attention to the calibration heuristics supported in CASA. Practical problems affecting modern instruments are also discussed.

  18. A multi-centre evaluation of the intra-assay and inter-assay variation of commercial and in-house anti-cardiolipin antibody assays.

    Science.gov (United States)

    Wong, Richard; Favaloro, Emmanuel; Pollock, Wendy; Wilson, Robert; Hendle, Michelle; Adelstein, Stephen; Baumgart, Karl; Homes, Paul; Smith, Stuart; Steele, Richard; Sturgess, Allan; Gillis, David

    2004-04-01

    To assess the intra-assay (intra-run) and inter-assay (inter-run) variation of commercial and in-house IgG and IgM anti-cardiolipin antibody (aCL) assays/kits, and to determine an appropriate maximum value for inclusion in consensus guidelines. Frozen aliquots of two patient specimens and one commercial control were sent to nine laboratories for the evaluation of eight commercial kits and one in-house assay. Intra-assay and inter-assay evaluations were performed with all three samples for IgG aCL, and one patient specimen for IgM aCL. The IgG and IgM aCL values varied considerably between the nine assays/kits. The majority of assays/kits demonstrated less than 20% intra-assay and inter-assay variation, with lower intra-assay and inter-assay variation observed with the commercial control. Single calibrator assays were not consistently associated with higher inter-assay variation than multi-point calibrator assays. An inter-assay coefficient of variation of 20% was determined to be an appropriate maximum value for inclusion in the Australasian aCL Working Party consensus guidelines. Improved standardisation between different assay/kits is still required.

  19. Syringe calibration factors and volume correction factors for the NPL secondary standard radionuclide calibrator

    CERN Document Server

    Tyler, D K

    2002-01-01

    The activity assay of a radiopharmaceutical administration to a patient is normally achieved via the use of a radionuclide calibrator. Because of the different geometries and elemental compositions between plastic syringes and glass vials, the calibration factors for syringes may well be significantly different from those for the glass containers. The magnitude of these differences depends on the energies of the emitted photons. For some radionuclides variations have been observed of 70 %, it is therefore important to recalibrate for syringes or use syringe calibration factors. Calibration factors and volume correction factors have been derived for the NPL secondary standard radionuclide calibrator, for a variety of commonly used syringes and needles, for the most commonly used medical radionuclide.

  20. Calibration of Geodetic Instruments

    Directory of Open Access Journals (Sweden)

    Marek Bajtala

    2005-06-01

    Full Text Available The problem of metrology and security systems of unification, correctness and standard reproducibilities belong to the preferred requirements of theory and technical practice in geodesy. Requirements on the control and verification of measured instruments and equipments increase and the importance and up-to-date of calibration get into the foreground. Calibration possibilities of length-scales (of electronic rangefinders and angle-scales (of horizontal circles of geodetic instruments. Calibration of electronic rangefinders on the linear comparative baseline in terrain. Primary standard of planar angle – optical traverse and its exploitation for calibration of the horizontal circles of theodolites. The calibration equipment of the Institute of Slovak Metrology in Bratislava. The Calibration process and results from the calibration of horizontal circles of selected geodetic instruments.

  1. Assaying Used Nuclear Fuel Assemblies Using Lead Slowing-Down Spectroscopy and Singular Value Decomposition

    Science.gov (United States)

    Kulisek, Jonathan A.; Anderson, Kevin K.; Casella, Andrew M.; Gesh, Chris J.; Warren, Glen A.

    2013-04-01

    This study investigates the use of a Lead Slowing-Down Spectrometer (LSDS) for the direct and independent measurement of fissile isotopes in light-water nuclear reactor fuel assemblies. The current study applies MCNPX, a Monte Carlo radiation transport code, to simulate the measurement of the assay of the used nuclear fuel assemblies in the LSDS. An empirical model has been developed based on the calibration of the LSDS to responses generated from the simulated assay of six well-characterized fuel assemblies. The effects of self-shielding are taken into account by using empirical basis vectors calculated from the singular value decomposition (SVD) of a matrix containing the self-shielding functions from the assay of assemblies in the calibration set. The performance of the empirical algorithm was tested on version 1 of the Next-Generation Safeguards Initiative (NGSI) used fuel library consisting of 64 assemblies, as well as a set of 27 diversion assemblies, both of which were developed by Los Alamos National Laboratory. The potential for direct and independent assay of the sum of the masses of Pu-239 and Pu-241 to within 2%, on average, has been demonstrated.

  2. Standard guide for making quality nondestructive assay measurements

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This guide is a compendium of Quality Measurement Practices for performing measurements of radioactive material using nondestructive assay (NDA) instruments. The primary purpose of the guide is to assist users in arriving at quality NDA results, that is, results that satisfy the end user’s needs. This is accomplished by providing an acceptable and uniform basis for the collection, analysis, comparison, and application of data. The recommendations are not compulsory or prerequisites to achieving quality NDA measurements, but are considered contributory in most areas. 1.2 This guide applies to the use of NDA instrumentation for the measurement of nuclear materials by the observation of spontaneous or stimulated nuclear radiations, including photons, neutrons, or the flow of heat. Recommended calibration, operating, and assurance methods represent guiding principles based on current NDA technology. The diversity of industry-wide nuclear materials measurement applications and instrumentation precludes disc...

  3. Marine X-band Weather Radar Data Calibration

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2012-01-01

    estimates. This paper presents some of the challenges in small marine X-band radar calibration by comparing three calibration procedures for assessing the relationship between radar and rain gauge data. Validation shows similar results for precipitation volumes but more diverse results on peak rain...

  4. Optimizing active and passive calibration of optical tweezers

    Science.gov (United States)

    Andersson, M.; Czerwinski, F.; Oddershede, L. B.

    2011-04-01

    To obtain quantitative information from optical trapping experiments it is essential to perform a precise force calibration. Therefore, sources of noise should be pinpointed and eliminated. Fourier analysis is routinely used to calibrate optical trapping assays because it is excellent for pinpointing high frequency noise. In addition, Allan variance analysis is particularly useful for quantifying low frequency noise and for predicting the optimal measurement time. We show how to use Allan variance in combination with Fourier analysis for optimal calibration and noise reduction in optical trapping assays. The methods are applied to passive assays, utilizing the thermal motion of a trapped particle, and to active assays where the bead is harmonically driven. The active method must be applied in assays where, for example, the viscoelastic properties of the medium or the size or shape of the trapped object are unknown. For measurement times shorter than the optimal calibration time the noise is larger in active than in the passive assays. For times equal to or longer than the optimal measurement time, though, the noise on passive and active assays is identical. As an example, we show how to quantify the influence on measurement noise of bead size and chamber geometry in active and passive assays.

  5. Site Calibration, FGW

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    This Site Calibration report is describing the results of a measured site calibration for a site in Denmark. The calibration is carried out by DTU Wind Energy in accordance with Ref.[3] and Ref.[4]. The measurement period is given. The site calibration is carried out before a power performance...... measurement on a given turbine to clarify the influence from the terrain on the ratio between the wind speed at the center of the turbine hub and at the met mast. The wind speed at the turbine is measured by a temporary mast placed at the foundation for the turbine. The site and measurement equipment...

  6. Site Calibration report

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Vesth, Allan

    This report describes the site calibration carried out at Østerild, during a given period. The site calibration was performed with two Windcube WLS7 (v1) lidars at ten measurements heights. The lidar is not a sensor approved by the current version of the IEC 61400-12-1 [1] and therefore the site...

  7. TWSTFT Link Calibration Report

    Science.gov (United States)

    2015-09-01

    Washington Headquarters Services , Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302...and Bauch A (2014) THE EUROPEAN TW CALIBRATION CAMPAIGN 2014 IN THE SCOPE OF GALILEO (TGVF- FOC), An opportunity to update, TW link calibrations in

  8. Lidar to lidar calibration

    DEFF Research Database (Denmark)

    Fernandez Garcia, Sergio; Villanueva, Héctor

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and correspondi...

  9. Sandia WIPP calibration traceability

    Energy Technology Data Exchange (ETDEWEB)

    Schuhen, M.D. [Sandia National Labs., Albuquerque, NM (United States); Dean, T.A. [RE/SPEC, Inc., Albuquerque, NM (United States)

    1996-05-01

    This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

  10. Lidar to lidar calibration

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Courtney, Michael

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and corresponding...... lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from the reference lidar measurements are given for information only....

  11. Approximation Behooves Calibration

    DEFF Research Database (Denmark)

    da Silva Ribeiro, André Manuel; Poulsen, Rolf

    2013-01-01

    Calibration based on an expansion approximation for option prices in the Heston stochastic volatility model gives stable, accurate, and fast results for S&P500-index option data over the period 2005–2009....

  12. SRHA calibration curve

    Data.gov (United States)

    U.S. Environmental Protection Agency — an UV calibration curve for SRHA quantitation. This dataset is associated with the following publication: Chang, X., and D. Bouchard. Surfactant-Wrapped Multiwalled...

  13. Air Data Calibration Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is for low altitude subsonic altimeter system calibrations of air vehicles. Mission is a direct support of the AFFTC mission. Postflight data merge is...

  14. SPOTS Calibration Example

    Directory of Open Access Journals (Sweden)

    Patterson E.

    2010-06-01

    Full Text Available The results are presented using the procedure outlined by the Standardisation Project for Optical Techniques of Strain measurement to calibrate a digital image correlation system. The process involves comparing the experimental data obtained with the optical measurement system to the theoretical values for a specially designed specimen. The standard states the criteria which must be met in order to achieve successful calibration, in addition to quantifying the measurement uncertainty in the system. The system was evaluated at three different displacement load levels, generating strain ranges from 289 µstrain to 2110 µstrain. At the 289 µstrain range, the calibration uncertainty was found to be 14.1 µstrain, and at the 2110 µstrain range it was found to be 28.9 µstrain. This calibration procedure was performed without painting a speckle pattern on the surface of the metal. Instead, the specimen surface was prepared using different grades of grit paper to produce the desired texture.

  15. Ames Balance Calibration Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Operations at the lab include calibrating balances for the Ames Wind Tunnels as well as for approved outside projects. Ames has a large inventory of TASK multi-piece...

  16. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina; Webb, Craig

    2016-05-02

    This presentation provides a high-level overview of the progress on the Broadband Outdoor Radiometer Calibrations for all shortwave and longwave radiometers that are deployed by the Atmospheric Radiation Measurement program.

  17. Jet Calibration at ATLAS

    CERN Document Server

    Camacho, R; The ATLAS collaboration

    2011-01-01

    The accurate measurement of jets at high transverse momentum produced in proton proton collision at a centre of mass energy at \\sqrt(s)=7 TeV is important in many physics analysis at LHC. Due to the non-compensating nature of the ATLAS calorimeter, signal losses due to noise thresholds and in dead material the jet energy needs to be calibrated. Presently, the ATLAS experiment derives the jet calibration from Monte Carlo simulation using a simple correction that relates the true and the reconstructed jet energy. The jet energy scale and its uncertainty are derived from in-situ measurements and variation in the Monte Carlo simulation. Other calibration schemes have been also developed, they use hadronic cell calibrations or the topology of the jet constituents to reduce hadronic fluctuations in the jet response, improving in that way the jet resolution. The performances of the various calibration schemes using data and simulation, the evaluation of the modelling of the properties used to derive each calibration...

  18. Calibrating nacelle lidars

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, M.

    2013-01-15

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail. The first of these is a line of sight calibration method in which both lines of sight (for a two beam lidar) are individually calibrated by accurately aligning the beam to pass close to a reference wind speed sensor. A testing procedure is presented, reporting requirements outlined and the uncertainty of the method analysed. It is seen that the main limitation of the line of sight calibration method is the time required to obtain a representative distribution of radial wind speeds. An alternative method is to place the nacelle lidar on the ground and incline the beams upwards to bisect a mast equipped with reference instrumentation at a known height and range. This method will be easier and faster to implement and execute but the beam inclination introduces extra uncertainties. A procedure for conducting such a calibration is presented and initial indications of the uncertainties given. A discussion of the merits and weaknesses of the two methods is given together with some proposals for the next important steps to be taken in this work. (Author)

  19. How Frequently Are Pan-Assay Interference Compounds Active? Large-Scale Analysis of Screening Data Reveals Diverse Activity Profiles, Low Global Hit Frequency, and Many Consistently Inactive Compounds.

    Science.gov (United States)

    Jasial, Swarit; Hu, Ye; Bajorath, Jürgen

    2017-05-11

    Undetected pan-assay interference compounds (PAINS) with false-positive activities in assays often propagate through medicinal chemistry programs and compromise their outcomes. Although a large number of PAINS have been classified, often on the basis of individual studies or chemical experience, little has been done so far to systematically assess their activity profiles. Herein we report a large-scale analysis of the behavior of PAINS in biological screening assays. More than 23 000 extensively tested compounds containing PAINS substructures were detected, and their hit rates were determined. Many consistently inactive compounds were identified. The hit frequency was low overall, with median values of two to five hits for PAINS tested in hundreds of assays. Only confined subsets of PAINS produced abundant hits. The same PAINS substructure was often found in consistently inactive and frequently active compounds, indicating that the structural context in which PAINS occur modulates their effects.

  20. Calibration Under Uncertainty.

    Energy Technology Data Exchange (ETDEWEB)

    Swiler, Laura Painton; Trucano, Timothy Guy

    2005-03-01

    This report is a white paper summarizing the literature and different approaches to the problem of calibrating computer model parameters in the face of model uncertainty. Model calibration is often formulated as finding the parameters that minimize the squared difference between the model-computed data (the predicted data) and the actual experimental data. This approach does not allow for explicit treatment of uncertainty or error in the model itself: the model is considered the %22true%22 deterministic representation of reality. While this approach does have utility, it is far from an accurate mathematical treatment of the true model calibration problem in which both the computed data and experimental data have error bars. This year, we examined methods to perform calibration accounting for the error in both the computer model and the data, as well as improving our understanding of its meaning for model predictability. We call this approach Calibration under Uncertainty (CUU). This talk presents our current thinking on CUU. We outline some current approaches in the literature, and discuss the Bayesian approach to CUU in detail.

  1. WFIRST WFI Calibration Requirements

    Science.gov (United States)

    Scolnic, Daniel; Casertano, Stephano; WFIRST Calibration Group

    2018-01-01

    The Wide Field InfraRed Survey Telescope (WFIRST), with a planned launch in the mid-2020’s, will enable multiple generation-defining measurements in astrophysics and cosmology. One of the key goals of the mission is to limit calibration uncertainties in order to enable a wide range of experiments. Here we present the work of the WFIRST WFI Calibration Working Group, which has compiled a comprehensive set of calibration needs derived from the Mission science requirements, and has outlined a plan toachieve them. In many areas, the accuracy required has yet to be reached in any comparable mission or project. We present here the various plans of on-ground characterization, pre-launch data; internal measurements and observations in orbit; and external observations.

  2. Site Calibration report

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Vesth, Allan

    The report describes site calibration measurements carried out on a site in Denmark. The measurements are carried out in accordance to Ref. [1]. The site calibration is carried out before a power performance measurement on a given turbine to clarify the influence from the terrain on the ratio...... between the wind speed at the center of the turbine hub and at the met mast. The wind speed at the turbine is measured by a temporary mast placed at the foundation for the turbine. The site and measurement equipment is detailed described in [2]. The possible measurement sector for power performance...... according to [1] is also described in [2] and no results from the site calibration have shown any necessary exclusion from this sector. All parts of the sensors and the measurement system have been installed by DTU....

  3. TARGETLESS CAMERA CALIBRATION

    Directory of Open Access Journals (Sweden)

    L. Barazzetti

    2012-09-01

    Full Text Available In photogrammetry a camera is considered calibrated if its interior orientation parameters are known. These encompass the principal distance, the principal point position and some Additional Parameters used to model possible systematic errors. The current state of the art for automated camera calibration relies on the use of coded targets to accurately determine the image correspondences. This paper presents a new methodology for the efficient and rigorous photogrammetric calibration of digital cameras which does not require any longer the use of targets. A set of images depicting a scene with a good texture are sufficient for the extraction of natural corresponding image points. These are automatically matched with feature-based approaches and robust estimation techniques. The successive photogrammetric bundle adjustment retrieves the unknown camera parameters and their theoretical accuracies. Examples, considerations and comparisons with real data and different case studies are illustrated to show the potentialities of the proposed methodology.

  4. Calibrating the Athena telescope

    Science.gov (United States)

    de Bruijne, J.; Guainazzi, M.; den Herder, J.; Bavdaz, M.; Burwitz, V.; Ferrando, P.; Lumb, D.; Natalucci, L.; Pajot, F.; Pareschi, G.

    2017-10-01

    Athena is ESA's upcoming X-ray mission, currently set for launch in 2028. With two nationally-funded, state-of-the-art instruments (a high-resolution spectrograph named X-IFU and a wide-field imager named WFI), and a telescope collecting area of 1.4-2 m^2 at 1 keV, the calibration of the spacecraft is a challenge in itself. This poster presents the current (spring 2017) plan of how to calibrate the Athena telescope. It is based on a hybrid approach, using bulk manufacturing and integration data as well as dedicated calibration measurements combined with a refined software model to simulate the full response of the optics.

  5. Deep Impact instrument calibration

    Science.gov (United States)

    Klaasen, K.; A'Hearn, M. F.; Baca, M.; Delamere, A.; Desnoyer, M.; Farnham, T.; Groussin, O.; Hampton, D.; Ipatov, S.; Li, J.-Y.; Lisse, C.; Mastrodemos, N.; McLaughlin, S.; Sunshine, J.; Thomas, P.; Wellnitz, D.

    2008-09-01

    Calibration of NASA's Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [~1.7 pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of ~9 pixels. The charge coupled device (CCD) read noise is ~1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is correctable to ~1%. Spectrometer read noise is ~2 DN. The variation in zero-exposure signal level with time and spectrometer temperature is not fully characterized; currently corrections are good to ~10 DN at best. Wavelength mapping onto the detector is known within 1 pixel; spectral lines have a FWHM of ~2 pixels. About 1% of the IR detector pixels behave badly and remain uncalibrated. The spectrometer exhibits a faint ghost image from reflection off a beamsplitter. Instrument absolute radiometric calibration accuracies were determined generally to <10% using star imaging. Flat-field calibration reduces pixel-to-pixel response differences to ~0.5% for the cameras and <2% for the spectrometer. A standard calibration image processing pipeline is used to produce archival image files for analysis by researchers.

  6. Calibration of scanning Lidar

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report describes the tests carried out on a scanning lidar at the DTU Test Station for large wind turbines, Høvsøre. The tests were divided in two parts. In the first part, the purpose was to obtain wind speed calibrations at two heights against two cup anemometers mounted on a mast. Additio......This report describes the tests carried out on a scanning lidar at the DTU Test Station for large wind turbines, Høvsøre. The tests were divided in two parts. In the first part, the purpose was to obtain wind speed calibrations at two heights against two cup anemometers mounted on a mast...

  7. Calibrated entanglement entropy

    Science.gov (United States)

    Bakhmatov, I.; Deger, N. S.; Gutowski, J.; Colgáin, E. Ó.; Yavartanoo, H.

    2017-07-01

    The Ryu-Takayanagi prescription reduces the problem of calculating entanglement entropy in CFTs to the determination of minimal surfaces in a dual anti-de Sitter geometry. For 3D gravity theories and BTZ black holes, we identify the minimal surfaces as special Lagrangian cycles calibrated by the real part of the holomorphic one-form of a spacelike hypersurface. We show that (generalised) calibrations provide a unified way to determine holographic entanglement entropy from minimal surfaces, which is applicable to warped AdS3 geometries. We briefly discuss generalisations to higher dimensions.

  8. Calibrating Legal Judgments

    Directory of Open Access Journals (Sweden)

    Frederick Schauer

    2017-09-01

    Full Text Available Objective to study the notion and essence of legal judgments calibration the possibilities of using it in the lawenforcement activity to explore the expenses and advantages of using it. Methods dialectic approach to the cognition of social phenomena which enables to analyze them in historical development and functioning in the context of the integrity of objective and subjective factors it determined the choice of the following research methods formallegal comparative legal sociological methods of cognitive psychology and philosophy. Results In ordinary life people who assess other peoplersaquos judgments typically take into account the other judgments of those they are assessing in order to calibrate the judgment presently being assessed. The restaurant and hotel rating website TripAdvisor is exemplary because it facilitates calibration by providing access to a raterrsaquos previous ratings. Such information allows a user to see whether a particular rating comes from a rater who is enthusiastic about every place she patronizes or instead from someone who is incessantly hard to please. And even when less systematized as in assessing a letter of recommendation or college transcript calibration by recourse to the decisional history of those whose judgments are being assessed is ubiquitous. Yet despite the ubiquity and utility of such calibration the legal system seems perversely to reject it. Appellate courts do not openly adjust their standard of review based on the previous judgments of the judge whose decision they are reviewing nor do judges in reviewing legislative or administrative decisions magistrates in evaluating search warrant representations or jurors in assessing witness perception. In most legal domains calibration by reference to the prior decisions of the reviewee is invisible either because it does not exist or because reviewing bodies are unwilling to admit using what they in fact know and employ. Scientific novelty for the first

  9. Calibration with Absolute Shrinkage

    DEFF Research Database (Denmark)

    Øjelund, Henrik; Madsen, Henrik; Thyregod, Poul

    2001-01-01

    is suggested to cope with the singular design matrix most often seen in chemometric calibration. Furthermore, the proposed algorithm may be generalized to all convex norms like Sigma/beta (j)/(gamma) where gamma greater than or equal to 1, i.e. a method that continuously varies from ridge regression...... to the lasso. The lasso is applied both directly as a calibration method and as a method to select important variables/wave lengths. It is demonstrated that the lasso algorithm, in general, leads to parameter estimates of which some are zero while others are quite large (compared to e.g. the traditional PLS...

  10. CLUSTERED RADIO INTERFEROMETRIC CALIBRATION

    NARCIS (Netherlands)

    Kazemi, S.; Yatawatta, S.; Zaroubi, S.

    2011-01-01

    This paper introduces an amendment to radio interferometric calibration of sources below the noise level. The main idea is to employ the information of the stronger sources' measured signals as a plug-in criterion to solve for the weaker ones. For this purpose, we construct a number of source

  11. NVLAP calibration laboratory program

    Energy Technology Data Exchange (ETDEWEB)

    Cigler, J.L.

    1993-12-31

    This paper presents an overview of the progress up to April 1993 in the development of the Calibration Laboratories Accreditation Program within the framework of the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST).

  12. Calibrating Communication Competencies

    Science.gov (United States)

    Surges Tatum, Donna

    2016-11-01

    The Many-faceted Rasch measurement model is used in the creation of a diagnostic instrument by which communication competencies can be calibrated, the severity of observers/raters can be determined, the ability of speakers measured, and comparisons made between various groups.

  13. ECAL Energy Flow Calibration

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    My talk will be covering my work as a whole over the course of the semester. The focus will be on using energy flow calibration in ECAL to check the precision of the corrections made by the light monitoring system used to account for transparency loss within ECAL crystals due to radiation damage over time.

  14. Entropic calibration revisited

    Energy Technology Data Exchange (ETDEWEB)

    Brody, Dorje C. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)]. E-mail: d.brody@imperial.ac.uk; Buckley, Ian R.C. [Centre for Quantitative Finance, Imperial College, London SW7 2AZ (United Kingdom); Constantinou, Irene C. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom); Meister, Bernhard K. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

    2005-04-11

    The entropic calibration of the risk-neutral density function is effective in recovering the strike dependence of options, but encounters difficulties in determining the relevant greeks. By use of put-call reversal we apply the entropic method to the time reversed economy, which allows us to obtain the spot price dependence of options and the relevant greeks.

  15. Measurement System & Calibration report

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Villanueva, Héctor

    This Measurement System & Calibration report is describing DTU’s measurement system installed at a specific wind turbine. A part of the sensors has been installed by others, the rest of the sensors have been installed by DTU. The results of the measurements, described in this report, are only val...

  16. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani; Susan S. Sorini

    2007-03-31

    The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

  17. Field calibration of cup anemometers

    DEFF Research Database (Denmark)

    Schmidt Paulsen, Uwe; Mortensen, Niels Gylling; Hansen, Jens Carsten

    2007-01-01

    A field calibration method and results are described along with the experience gained with the method. The cup anemometers to be calibrated are mounted in a row on a 10-m high rig and calibrated in the free wind against a reference cup anemometer. The method has been reported [1] to improve...... the statistical bias on the data relative to calibrations carried out in a wind tunnel. The methodology is sufficiently accurate for calibration of cup anemometers used for wind resource assessments and provides a simple, reliable and cost-effective solution to cup anemometer calibration, especially suited...

  18. Mercury Calibration System

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Eric Kalberer; Joseph Rovani; Mark Sanderson; Ryan Boysen; William Schuster

    2009-03-11

    U.S. Environmental Protection Agency (EPA) Performance Specification 12 in the Clean Air Mercury Rule (CAMR) states that a mercury CEM must be calibrated with National Institute for Standards and Technology (NIST)-traceable standards. In early 2009, a NIST traceable standard for elemental mercury CEM calibration still does not exist. Despite the vacature of CAMR by a Federal appeals court in early 2008, a NIST traceable standard is still needed for whatever regulation is implemented in the future. Thermo Fisher is a major vendor providing complete integrated mercury continuous emissions monitoring (CEM) systems to the industry. WRI is participating with EPA, EPRI, NIST, and Thermo Fisher towards the development of the criteria that will be used in the traceability protocols to be issued by EPA. An initial draft of an elemental mercury calibration traceability protocol was distributed for comment to the participating research groups and vendors on a limited basis in early May 2007. In August 2007, EPA issued an interim traceability protocol for elemental mercury calibrators. Various working drafts of the new interim traceability protocols were distributed in late 2008 and early 2009 to participants in the Mercury Standards Working Committee project. The protocols include sections on qualification and certification. The qualification section describes in general terms tests that must be conducted by the calibrator vendors to demonstrate that their calibration equipment meets the minimum requirements to be established by EPA for use in CAMR monitoring. Variables to be examined include linearity, ambient temperature, back pressure, ambient pressure, line voltage, and effects of shipping. None of the procedures were described in detail in the draft interim documents; however they describe what EPA would like to eventually develop. WRI is providing the data and results to EPA for use in developing revised experimental procedures and realistic acceptance criteria based on

  19. UV irradiance radiometers calibration procedure

    OpenAIRE

    Doctorovich I. V.; Butenko V. K.; Hodovaniouk V. N.; Fodchuk I. M.; Yuriev V. G.

    2008-01-01

    The paper deals with the problems arising at calibration of narrow-band spectral-sensitive radiometers. The procedure of irradiance unit transfer to UV radiometers — UV radiometers calibration procedure — is presented.

  20. Calibrated kallikrein generation in human plasma

    DEFF Research Database (Denmark)

    Biltoft, D; Sidelmann, J J; Olsen, L F

    2016-01-01

    OBJECTIVES: The physiological role of the contact system remains inconclusive. No obvious clinical complications have been observed for factor XII (FXII), prekallikrein (PK), or high molecular weight kininogen deficiencies even though the contact system in vitro is associated with coagulation......, fibrinolysis, and inflammation. A global generation assay measuring the initial phase of the contact system could be a valuable tool for studies of its physiological role. DESIGN AND METHODS: We investigated whether such a method could be developed using the principle of the Calibrated Automated Thrombin...

  1. Lidar calibration experiments

    DEFF Research Database (Denmark)

    Ejsing Jørgensen, Hans; Mikkelsen, T.; Streicher, J.

    1997-01-01

    A series of atmospheric aerosol diffusion experiments combined with lidar detection was conducted to evaluate and calibrate an existing retrieval algorithm for aerosol backscatter lidar systems. The calibration experiments made use of two (almost) identical mini-lidar systems for aerosol cloud...... detection to test the reproducibility and uncertainty of lidars. Lidar data were obtained from both single-ended and double-ended Lidar configurations. A backstop was introduced in one of the experiments and a new method was developed where information obtained from the backstop can be used in the inversion...... algorithm. Independent in-situ aerosol plume concentrations were obtained from a simultaneous tracer gas experiment with SF6, and comparisons with the two lidars were made. The study shows that the reproducibility of the lidars is within 15%, including measurements from both sides of a plume...

  2. Calibrated vapor generator source

    Science.gov (United States)

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  3. Calibrated Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    H. H. Liu

    2003-02-14

    This report has documented the methodologies and the data used for developing rock property sets for three infiltration maps. Model calibration is necessary to obtain parameter values appropriate for the scale of the process being modeled. Although some hydrogeologic property data (prior information) are available, these data cannot be directly used to predict flow and transport processes because they were measured on scales smaller than those characterizing property distributions in models used for the prediction. Since model calibrations were done directly on the scales of interest, the upscaling issue was automatically considered. On the other hand, joint use of data and the prior information in inversions can further increase the reliability of the developed parameters compared with those for the prior information. Rock parameter sets were developed for both the mountain and drift scales because of the scale-dependent behavior of fracture permeability. Note that these parameter sets, except those for faults, were determined using the 1-D simulations. Therefore, they cannot be directly used for modeling lateral flow because of perched water in the unsaturated zone (UZ) of Yucca Mountain. Further calibration may be needed for two- and three-dimensional modeling studies. As discussed above in Section 6.4, uncertainties for these calibrated properties are difficult to accurately determine, because of the inaccuracy of simplified methods for this complex problem or the extremely large computational expense of more rigorous methods. One estimate of uncertainty that may be useful to investigators using these properties is the uncertainty used for the prior information. In most cases, the inversions did not change the properties very much with respect to the prior information. The Output DTNs (including the input and output files for all runs) from this study are given in Section 9.4.

  4. Evaluation of four simple/rapid assays and two fourth-generation ELISAs for the identification of HIV infection on a serum panel representing the HIV-1 group M genetic diversity in Cameroon.

    Science.gov (United States)

    Aghokeng, Avelin Fobang; Ewane, Léonard; Awazi, Bih; Nanfack, Aubin; Delaporte, Eric; Peeters, Martine; Zekeng, Léopold

    2004-12-15

    The performance of 4 rapid and simple assays: Camstix-HIV 1+2 (Camdiagnostix, Yaounde, Cameroon); Determine HIV 1+2+0 (Abbott Laboratories, Tokyo, Japan); Genie II HIV-1/HIV-2 (Bio-Rad, Marnes la Coquette, France); ImmunoComb II HIV 1 & 2 BiSpot (Orgenics, Yavne, Israel); and 2 fourth-generation ELISAs: Enzygnost HIV Integral (Dade Behring, Marburg, Germany) and Genscreen plus HIV Ag-Ab (Bio-Rad, Marnes la Coquette, France) currently used in Cameroon to detect HIV infections were evaluated on a local serum panel. A total of 503 samples were collected, using the Camstix-HIV 1+2 assay. Overall, 280 samples were confirmed HIV positive, 181 were negative, and 42 were indeterminate. All positive samples belonged to group M: CRF02_AG (73.5%), A1 (7.1%), A2 (1.2%), G (4.7%), F2 (5.1%), D (1.6%), CRF11 (1.6%), CRF06 (1.2%), and CRF01_AE (1.6%). Sensitivity, specificity, test efficiency, and positive and negative predictive values were calculated both including and excluding indeterminate samples. Except for Genie II and ImmunoComb II (98.9 and 99.3%, respectively), sensitivities were 100% for the remaining 4 tests. Specificities, efficiencies, and positive predictive values of all assays were negatively affected by the addition of HIV-indeterminate samples in the calculations. These data show the importance of prior test evaluations on local serum panels and in field conditions before a national policy for HIV screening is decided on and stress also the need to use tests and algorithms that can reduce the high number of HIV-indeterminate results in Africa.

  5. CALIBRATED HYDRODYNAMIC MODEL

    Directory of Open Access Journals (Sweden)

    Sezar Gülbaz

    2015-01-01

    Full Text Available The land development and increase in urbanization in a watershed affect water quantityand water quality. On one hand, urbanization provokes the adjustment of geomorphicstructure of the streams, ultimately raises peak flow rate which causes flood; on theother hand, it diminishes water quality which results in an increase in Total SuspendedSolid (TSS. Consequently, sediment accumulation in downstream of urban areas isobserved which is not preferred for longer life of dams. In order to overcome thesediment accumulation problem in dams, the amount of TSS in streams and inwatersheds should be taken under control. Low Impact Development (LID is a BestManagement Practice (BMP which may be used for this purpose. It is a land planningand engineering design method which is applied in managing storm water runoff inorder to reduce flooding as well as simultaneously improve water quality. LID includestechniques to predict suspended solid loads in surface runoff generated over imperviousurban surfaces. In this study, the impact of LID-BMPs on surface runoff and TSS isinvestigated by employing a calibrated hydrodynamic model for Sazlidere Watershedwhich is located in Istanbul, Turkey. For this purpose, a calibrated hydrodynamicmodel was developed by using Environmental Protection Agency Storm WaterManagement Model (EPA SWMM. For model calibration and validation, we set up arain gauge and a flow meter into the field and obtain rainfall and flow rate data. Andthen, we select several LID types such as retention basins, vegetative swales andpermeable pavement and we obtain their influence on peak flow rate and pollutantbuildup and washoff for TSS. Consequently, we observe the possible effects ofLID on surface runoff and TSS in Sazlidere Watershed.

  6. Smart Calibration of Excavators

    DEFF Research Database (Denmark)

    Bro, Marie; Døring, Kasper; Ellekilde, Lars-Peter

    2005-01-01

    Excavators dig holes. But where is the bucket? The purpose of this report is to treat four different problems concerning calibrations of position indicators for excavators in operation at concrete construction sites. All four problems are related to the question of how to determine the precise...... geographic and/or site-relative position of a given excavator and its bucket. However, our presentations and solutions to the problems can, nevertheless, be read and studied in any order and independently of each other. This also implies and induces a gentle warning to the reader: The {\\em{notation}} need...

  7. Local Hadronic Calibration

    CERN Document Server

    Barillari, T; Carli, T; Erdmann, J; Giovannini, P; Grahn, K J; Issever, C; Jantsch, A; Kiryunin, A; Lohwasser, K; Maslennikov, A; Menke, S; Oberlack, H; Pospelov, G; Rauter, E; Schacht, P; Spanó, F; Speckmayer, P; Stavina, P; Strízenec, P

    2008-01-01

    The scheme of the hadronic calibration is discussed. Based on the cluster reconstruction an effective noise suppression is achieved. In a first step clusters are classified as electromagnetic or hadronic clusters. The weighting scheme to correct for the different e/pion response in the ATLAS calorimeter is presented. Dead material corrections and out of cluster corrections yield finally a signal which is rather close to the energy deposited by the final state particles in the ATLAS calorimeter. The constants and algorithms are derived from single pion MC studies and tested with jets. The validation of the scheme using testbeam data is presented as well.

  8. ALTEA: The instrument calibration

    Energy Technology Data Exchange (ETDEWEB)

    Zaconte, V. [INFN and University of Rome Tor Vergata, Department of Physics, Via della Ricerca Scientifica 1, 00133 Rome (Italy)], E-mail: livio.narici@roma2.infn.it; Belli, F.; Bidoli, V.; Casolino, M.; Di Fino, L.; Narici, L.; Picozza, P.; Rinaldi, A. [INFN and University of Rome Tor Vergata, Department of Physics, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Sannita, W.G. [DISM, University of Genova, Genova (Italy); Department of Psychiatry, SUNY, Stoony Brook, NY (United States); Finetti, N.; Nurzia, G.; Rantucci, E.; Scrimaglio, R.; Segreto, E. [Department of Physics, University and INFN, L' Aquila (Italy); Schardt, D. [GSI/Biophysik, Darmstadt (Germany)

    2008-05-15

    The ALTEA program is an international and multi-disciplinary project aimed at studying particle radiation in space environment and its effects on astronauts' brain functions, as the anomalous perception of light flashes first reported during Apollo missions. The ALTEA space facility includes a 6-silicon telescopes particle detector, and is onboard the International Space Station (ISS) since July 2006. In this paper, the detector calibration at the heavy-ion synchrotron SIS18 at GSI Darmstadt will be presented and compared to the Geant 3 Monte Carlo simulation. Finally, the results of a neural network analysis that was used for ion discrimination on fragmentation data will also be presented.

  9. A Simple Accelerometer Calibrator

    Science.gov (United States)

    Salam, R. A.; Islamy, M. R. F.; Munir, M. M.; Latief, H.; Irsyam, M.; Khairurrijal

    2016-08-01

    High possibility of earthquake could lead to the high number of victims caused by it. It also can cause other hazards such as tsunami, landslide, etc. In that case it requires a system that can examine the earthquake occurrence. Some possible system to detect earthquake is by creating a vibration sensor system using accelerometer. However, the output of the system is usually put in the form of acceleration data. Therefore, a calibrator system for accelerometer to sense the vibration is needed. In this study, a simple accelerometer calibrator has been developed using 12 V DC motor, optocoupler, Liquid Crystal Display (LCD) and AVR 328 microcontroller as controller system. The system uses the Pulse Wave Modulation (PWM) form microcontroller to control the motor rotational speed as response to vibration frequency. The frequency of vibration was read by optocoupler and then those data was used as feedback to the system. The results show that the systems could control the rotational speed and the vibration frequencies in accordance with the defined PWM.

  10. Optical calibration of SNO +

    Science.gov (United States)

    Leming, Edward; SNO+ Collaboration

    2015-04-01

    Situated 2 km underground in Sudbury, Northern Ontario, the SNO + detector consists of an acrylic sphere 12 m in diameter containing 780 tons of target mass, surrounded by approximately 9,500 PMTs. For SNO, this target mass was heavy water, however the change to SNO + is defined by the change of this target mass to a novel scintillator. With the lower energy threshold, low intrinsic radioactivity levels and the best shielding against muons and cosmogenic activation of all existing neutrino experiments, SNO + will be sensitive to exciting new physics. The experiment will be studying solar, reactor, super nova and geo-neutrinos, though the main purpose of SNO + is the search for neutrinoless double-beta decay of Te-130. To meet the requirements imposed by the physics on detector performance, a detailed optical calibration is needed. Source deployment must be kept to a minimum and eliminated if possible, in order to meet the stringent radiopurity requirements. This led to the development of the Embedded LED/laser Light Injection Entity (ELLIE) system. This talk provides a summary of the upgrades to from SNO to SNO +, discussing the requirements on and methods of optical calibration, focusing on the deployed laserball and ELLIE system.

  11. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas

    2013-01-21

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  12. On chromatic and geometrical calibration

    DEFF Research Database (Denmark)

    Folm-Hansen, Jørgen

    1999-01-01

    The main subject of the present thesis is different methods for the geometrical and chromatic calibration of cameras in various environments. For the monochromatic issues of the calibration we present the acquisition of monochrome images, the classic monochrome aberrations and the various sources...... to design calibration targets for both geometrical and chromatic calibration are described. We present some possible systematical errors on the detection of the objects in the calibration targets, if viewed in a non orthogonal angle, if the intensities are uneven or if the image blurring is uneven. Finally...... of non-uniformity of the illumination of the image plane. Only the image deforming aberrations and the non-uniformity of illumination are included in the calibration models. The topics of the pinhole camera model and the extension to the Direct Linear Transform (DLT) are described. It is shown how...

  13. Satellite imager calibration and validation

    CSIR Research Space (South Africa)

    Vhengani, L

    2010-10-01

    Full Text Available and Validation Lufuno Vhengani*, Minette Lubbe, Derek Griffith and Meena Lysko Council for Scientific and Industrial Research, Defence Peace Safety and Security, Pretoria, South Africa E-mail: * lvhengani@csir.co.za Abstract: The success or failure... sensor designs incorporate onboard calibration instruments to facilitate post-launch characterisation. However, on-board calibrators are also susceptible to degradation over time. Therefore, post-launch calibration is made possible by taking in...

  14. On chromatic and geometrical calibration

    OpenAIRE

    Folm-Hansen, Jørgen

    1999-01-01

    The main subject of the present thesis is different methods for the geometrical and chromatic calibration of cameras in various environments. For the monochromatic issues of the calibration we present the acquisition of monochrome images, the classic monochrome aberrations and the various sources of non-uniformity of the illumination of the image plane. Only the image deforming aberrations and the non-uniformity of illumination are included in the calibration models. The topics of the pinhole...

  15. Radiological Calibration and Standards Facility

    Data.gov (United States)

    Federal Laboratory Consortium — PNNL maintains a state-of-the-art Radiological Calibration and Standards Laboratory on the Hanford Site at Richland, Washington. Laboratory staff provide expertise...

  16. SURF Model Calibration Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-10

    SURF and SURFplus are high explosive reactive burn models for shock initiation and propagation of detonation waves. They are engineering models motivated by the ignition & growth concept of high spots and for SURFplus a second slow reaction for the energy release from carbon clustering. A key feature of the SURF model is that there is a partial decoupling between model parameters and detonation properties. This enables reduced sets of independent parameters to be calibrated sequentially for the initiation and propagation regimes. Here we focus on a methodology for tting the initiation parameters to Pop plot data based on 1-D simulations to compute a numerical Pop plot. In addition, the strategy for tting the remaining parameters for the propagation regime and failure diameter is discussed.

  17. RX130 Robot Calibration

    Science.gov (United States)

    Fugal, Mario

    2012-10-01

    In order to create precision magnets for an experiment at Oak Ridge National Laboratory, a new reverse engineering method has been proposed that uses the magnetic scalar potential to solve for the currents necessary to produce the desired field. To make the magnet it is proposed to use a copper coated G10 form, upon which a drill, mounted on a robotic arm, will carve wires. The accuracy required in the manufacturing of the wires exceeds nominal robot capabilities. However, due to the rigidity as well as the precision servo motor and harmonic gear drivers, there are robots capable of meeting this requirement with proper calibration. Improving the accuracy of an RX130 to be within 35 microns (the accuracy necessary of the wires) is the goal of this project. Using feedback from a displacement sensor, or camera and inverse kinematics it is possible to achieve this accuracy.

  18. Marsis Calibration Plan

    Science.gov (United States)

    Jordan, R.; Safaeinili, A.; Kofman, W.; Picardi, G.

    MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) is the first of a new generation of radio sounders. MARSIS will be flown on the ESA Mars Express spacecraft. It will arrive at Mars in early 2004 for a two-year mission. MAR- SIS is the result of an international collaboration between NASA, the Italian Space Agency (ASI), and European Space Agency (ESA), is designed to sense planets in- terior to a depth of up to 5 km. MARSISS main objective is to search for water if it exists in liquid form under the surface. It will also attempt to map and characterize the subsurface geological structure of Mars, which is hidden under a layer of surface dust. In addition to its subsurface exploration goals, MARSIS will study the ionosphere of Mars providing the most extensive amount of data on Martian ionosphere to date. One of the main challenges of MARSIS is the calibration of the sounder instrument. The main objective of MARSIS is to probe the subsurface of Mars using low fre- quency radio waves and provide science data related to the electromagnetic behavior of the surface and subsurface. However, the sounder data is impacted by the instru- ment response and other environmental factors such as the ionosphere, Mars magnetic field and surface clutter. Removal from the scientific data of these effects will involve testing on the ground before flight and data acquisition after Mars orbit insertion. Re- moval of the effects of surface clutter will use avail-able digital terrain maps of Mars provided by the MGS Mars Orbiter Laser Altimeter (MOLA) team. This talk will highlight the calibration activities for MARSIS.

  19. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  20. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  1. Evaluation of real-time PCR assays and standard curve optimisation for enhanced accuracy in quantification of Campylobacter environmental water isolates.

    Science.gov (United States)

    Gosselin-Théberge, Maxime; Taboada, Eduardo; Guy, Rebecca A

    2016-10-01

    Campylobacter is a major public health and economic burden in developed and developing countries. This study evaluated published real-time PCR (qPCR) assays for detection of Campylobacter to enable selection of the best assays for quantification of C. spp. and C. jejuni in environmental water samples. A total of 9 assays were compared: three for thermotolerant C. spp. targeting the 16S rRNA and six for C. jejuni targeting different genes. These assays were tested in the wet-lab for specificity and sensitivity against a collection of 60, genetically diverse, Campylobacter isolates from environmental water. All three qPCR assays targeting C. spp. were positive when tested against the 60 isolates, whereas, assays targeting C. jejuni differed among each other in terms of specificity and sensitivity. Three C. jejuni-specific assays that demonstrated good specificity and sensitivity when tested in the wet-lab showed concordant results with in silico-predicted results obtained against a set of 211 C. jejuni and C. coli genome sequences. Two of the assays targeting C. spp. and C. jejuni were selected to compare DNA concentration estimation, using spectrophotometry and digital PCR (dPCR), in order to calibrate standard curves (SC) for greater accuracy of qPCR-based quantification. Average differences of 0.56±0.12 and 0.51±0.11 log fold copies were observed between the spectrophotometry-based SC preparation and the dPCR preparation for C. spp. and C. jejuni, respectively, demonstrating an over-estimation of Campylobacter concentration when spectrophotometry was used to calibrate the DNA SCs. Our work showed differences in quantification of aquatic environmental isolates of Campylobacter between qPCR assays and method-specific bias in SC preparation. This study provided an objective analysis of qPCR assays targeting Campylobacter in the literature and provides a framework for evaluating novel assays. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  2. Diversity Index

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — This map service summarizes racial and ethnic diversity in the United States in 2012.The Diversity Index shows the likelihood that two persons chosen at random from...

  3. Diversity & Dartmouth.

    Science.gov (United States)

    Freedman, James O.

    1991-01-01

    The president of Dartmouth College (New Hampshire) discusses campus cultural pluralism, the need for diversity in higher education, overcoming resistance to change, techniques for supporting a diverse student population, monitoring diversity through institutional research, and the issue of "political correctness" in higher education…

  4. Embracing Diversity

    NARCIS (Netherlands)

    S. Puntoni (Stefano)

    2015-01-01

    markdownabstract__Abstract__ Societies are vastly more diverse today than they used to be and, in many industries, developing theories and approaches that recognize and capitalize on this greater consumer diversity is crucial. In business schools, diversity tends to be discussed only in relation

  5. Field calibration of cup anemometers

    DEFF Research Database (Denmark)

    Kristensen, L.; Jensen, G.; Hansen, A.

    2001-01-01

    An outdoor calibration facility for cup anemometers, where the signals from 10 anemometers of which at least one is a reference can be can be recorded simultaneously, has been established. The results are discussed with special emphasis on the statisticalsignificance of the calibration expressions...

  6. Relational diversity.

    Science.gov (United States)

    Gregorius, Hans-Rolf

    2009-03-07

    In biology, the measurement of diversity traditionally focusses on reporting number of unambiguously distinguishable types, thus referring to qualitative (discontinuously varying) traits. Inclusion of frequencies or other weights has produced a large variety of diversity indices. Quantitative (continuously varying) traits do not readily fit into this perspective. In fact, in the context of quantitative traits, the concept of diversity is not always clearly distinguished from the (statistical) notion of dispersion. In many cases the ambiguity even extends to qualitative traits. This is at variance with the broad spectrum of diversity issues ranging, e.g., from ecological and genetic aspects of diversity to functional, structural, systematic, or evolutionary (including phylogenetic) aspects. In view of the urgent need for a more consistent perspective, it is called to attention that all of these aspects, whether of qualitative or quantitative nature, can be gathered under the common roof of binary relations (for qualitative traits two objects are related, for example, if they share the same trait state). A comprehensive concept of (relational) diversity can be developed in two steps: (1) determine the number of unrelated pairs of objects among all admissible pairs as a measure of implicit (relative) diversity, (2) invoke the concept of effective number to transform the implicit measure of diversity into an explicit (absolute) measure. The transformation operates by equating the observed implicit diversity to the implicit diversity obtained for the ideal model of an equivalence relation with classes of equal size. The number of these classes specifies the effective number as an explicit measure of diversity. The wealth of problems that can be treated from this unified perspective is briefly addressed by classifying and interpreting established diversity indices in the light of relational diversity. Desirable applications to the above-mentioned aspects are specified

  7. TIME CALIBRATED OSCILLOSCOPE SWEEP CIRCUIT

    Science.gov (United States)

    Smith, V.L.; Carstensen, H.K.

    1959-11-24

    An improved time calibrated sweep circuit is presented, which extends the range of usefulness of conventional oscilloscopes as utilized for time calibrated display applications in accordance with U. S. Patent No. 2,832,002. Principal novelty resides in the provision of a pair of separate signal paths, each of which is phase and amplitude adjustable, to connect a high-frequency calibration oscillator to the output of a sawtooth generator also connected to the respective horizontal deflection plates of an oscilloscope cathode ray tube. The amplitude and phase of the calibration oscillator signals in the two signal paths are adjusted to balance out feedthrough currents capacitively coupled at high frequencies of the calibration oscillator from each horizontal deflection plate to the vertical plates of the cathode ray tube.

  8. Local hadron calibration with ATLAS

    CERN Document Server

    Giovannini, P; The ATLAS collaboration

    2010-01-01

    The method of Local Hadron Calibration is used in ATLAS as one of the two major calibration schemes for the reconstruction of jets and missing transverse energy. The method starts from noise suppressed clusters and corrects them for non-compensation effects and for losses due to noise threshold and dead material. Jets are reconstructed on the calibrated clusters and are then corrected for out of cone effects. The performance of the corrections applied to the calorimeter clusters is tested with detailed GEANT4 information. Results obtained with this procedure are discussed both for single pion simulations and for di-jet simulations. The calibration schema is validated on data, by comparing the calibrated cluster energy with data and Mote Carlo simulations. Preliminary results obtained with sqrt(s)=900 GeV are presented. The agreement between data and Monte Carlo is inside 5% for the final cluster scale.

  9. Antenna Calibration and Measurement Equipment

    Science.gov (United States)

    Rochblatt, David J.; Cortes, Manuel Vazquez

    2012-01-01

    A document describes the Antenna Calibration & Measurement Equipment (ACME) system that will provide the Deep Space Network (DSN) with instrumentation enabling a trained RF engineer at each complex to perform antenna calibration measurements and to generate antenna calibration data. This data includes continuous-scan auto-bore-based data acquisition with all-sky data gathering in support of 4th order pointing model generation requirements. Other data includes antenna subreflector focus, system noise temperature and tipping curves, antenna efficiency, reports system linearity, and instrument calibration. The ACME system design is based on the on-the-fly (OTF) mapping technique and architecture. ACME has contributed to the improved RF performance of the DSN by approximately a factor of two. It improved the pointing performances of the DSN antennas and productivity of its personnel and calibration engineers.

  10. Digital camera self-calibration

    Science.gov (United States)

    Fraser, Clive S.

    Over the 25 years since the introduction of analytical camera self-calibration there has been a revolution in close-range photogrammetric image acquisition systems. High-resolution, large-area 'digital' CCD sensors have all but replaced film cameras. Throughout the period of this transition, self-calibration models have remained essentially unchanged. This paper reviews the application of analytical self-calibration to digital cameras. Computer vision perspectives are touched upon, the quality of self-calibration is discussed, and an overview is given of each of the four main sources of departures from collinearity in CCD cameras. Practical issues are also addressed and experimental results are used to highlight important characteristics of digital camera self-calibration.

  11. Diversity of Staphylococcus Species Strains Based on Partial kat (Catalase) Gene Sequences and Design of a PCR-Restriction Fragment Length Polymorphism Assay for Identification and Differentiation of Coagulase-Positive Species (S. aureus, S. delphini, S. hyicus, S. intermedius, S. pseudintermedius, and S. schleiferi subsp. coagulans)▿

    Science.gov (United States)

    Blaiotta, Giuseppe; Fusco, Vincenzina; Ercolini, Danilo; Pepe, Olimpia; Coppola, Salvatore

    2010-01-01

    A set of degenerate PCR primers was designed and used to amplify and sequence about 75% of the catalase (kat) gene from each of 49 staphylococcal strains. In some strains of Staphylococcus xylosus, S. saprophyticus, and S. equorum, two catalase genes, katA and katB, were found. A phylogenetic tree was generated and showed diversities among 66 partial (about 900-bp) staphylococcal kat nucleotide sequences (including 17 sequences found in GenBank) representing 26 different species. The topology of this tree showed a distribution of staphylococcal species similar, but not identical, to those reported previously based on 16S rRNA, hsp60, sodA, rpoB, tuf, and gap genes. The kat gene sequences were less conserved than those of 16S rRNA, rpoB, hsp60, and tuf genes and slightly more conserved than those of the gap gene. Therefore, kat gene sequence analysis may provide an additional marker for inferring phylogenetic relationships of staphylococci. Moreover, the discrete nucleotide polymorphism revealed in this gene could be exploited for rapid, low-cost identification of staphylococcal species through PCR-restriction fragment length polymorphism (RFLP) analysis. In this study, a PCR-RFLP assay performed by using only the TaqI restriction enzyme was successfully developed for rapid unequivocal identification/differentiation, at species and subspecies levels, of coagulase-positive staphylococci (CPS). The assay was validated by testing the DNA from 100 staphylococcal strains, including reference and wild CPS strains isolated from different environments. This reliable, rapid, and low-cost approach (requiring about 6 h from DNA isolation to the achievement of results and <5 Euros for each strain tested) allowed unambiguous identification of all the strains assayed, including the newly described S. delphini and S. pseudintermedius CPS species. PMID:19889901

  12. Challenges in X-band Weather Radar Data Calibration

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Rasmussen, Michael R.

    2009-01-01

    Application of weather radar data in urban hydrology is evolving and radar data is now applied for both modelling, analysis and real time control purposes. In these contexts, it is all-important that the radar data well calibrated and adjusted in order to obtain valid quantitative precipitation e...... estimates. This paper compares two calibration procedures for a small marine X-band radar by comparing radar data with rain gauge data. Validation shows a very good consensus with regards to precipitation volumes, but more diverse results on peak rain intensities....

  13. Identity, Diversity and Diversity Management

    DEFF Research Database (Denmark)

    Holck, Lotte; Muhr, Sara Louise; Villeseche, Florence

    2016-01-01

    The purpose of this paper is to examine the relationship between the identity and diversity literatures and discuss how a better understanding of the theoretical connections between the two informs both diversity research and diversity management practices. Design/methodology/approach – Literatur...

  14. Mercury Continuous Emmission Monitor Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Eric Kalberer; Ryan Boysen; William Schuster; Joseph Rovani

    2009-03-12

    Mercury continuous emissions monitoring systems (CEMs) are being implemented in over 800 coal-fired power plant stacks throughput the U.S. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor calibrators/generators. These devices are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 and vacated by a Federal appeals court in early 2008 required that calibration be performed with NIST-traceable standards. Despite the vacature, mercury emissions regulations in the future will require NIST traceable calibration standards, and EPA does not want to interrupt the effort towards developing NIST traceability protocols. The traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued a conceptual interim traceability protocol for elemental mercury calibrators. The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The EPA traceability protocol document is divided into two separate sections. The first deals with the qualification of calibrator models by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the calibrators that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma

  15. Mexican national pyronometer network calibration

    Science.gov (United States)

    VAldes, M.; Villarreal, L.; Estevez, H.; Riveros, D.

    2013-12-01

    In order to take advantage of the solar radiation as an alternate energy source it is necessary to evaluate the spatial and temporal availability. The Mexican National Meterological Service (SMN) has a network with 136 meteorological stations, each coupled with a pyronometer for measuring the global solar radiation. Some of these stations had not been calibrated in several years. The Mexican Department of Energy (SENER) in order to count on a reliable evaluation of the solar resource funded this project to calibrate the SMN pyrometer network and validate the data. The calibration of the 136 pyronometers by the intercomparison method recommended by the World Meterological Organization (WMO) requires lengthy observations and specific environmental conditions such as clear skies and a stable atmosphere, circumstances that determine the site and season of the calibration. The Solar Radiation Section of the Instituto de Geofísica of the Universidad Nacional Autónoma de México is a Regional Center of the WMO and is certified to carry out the calibration procedures and emit certificates. We are responsible for the recalibration of the pyronometer network of the SMN. A continuous emission solar simulator with exposed areas with 30cm diameters was acquired to reduce the calibration time and not depend on atmospheric conditions. We present the results of the calibration of 10 thermopile pyronometers and one photovoltaic cell by the intercomparison method with more than 10000 observations each and those obtained with the solar simulator.

  16. CMR Shuffler System: Passive Mode Calibration and Certification Report

    Energy Technology Data Exchange (ETDEWEB)

    Frame, Katherine C. [Los Alamos National Laboratory; Gomez, Cipriano D. [Retired CMR-OPS: OPERATIONS; Salazar, William R. [Los Alamos National Laboratory; Mayo, Douglas R. [Los Alamos National Laboratory; Vigil, Georgiana M. [Los Alamos National Laboratory; Crooks, William J. [Los Alamos National Laboratory; Stange, Sy [Los Alamos National Laboratory

    2012-07-20

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. As debris is removed from the vessels, material will be placed in waste drums. Far-field gamma ray assay will be used to determine when a drum is nearing a {sup 239}Pu equivalent mass of less than 200 g. The drum will then be assayed using a waste drum shuffler operated in passive mode using a neutron coincidence counting method for accountability. This report focuses on the testing and calibration of the CMR waste drum shuffler in passive mode operation. Initial testing was performed to confirm previously accepted measurement parameters. The system was then calibrated using a set of weapons grade Pu (WGPu, {sup 239}Pu > 93%) oxide standards placed inside a 55 gallon drum. The calibration data ranges from Pu mass of 0.5 g to 188.9 g. The CMR waste drum shuffler has been tested and calibrated in passive mode in preparation for safeguards accountability measurements of waste drums containing material removed from CVs for the CVD project.

  17. A Quantitative Fluorescence-Based Lipase Assay

    Directory of Open Access Journals (Sweden)

    Giovanna Lomolino

    2012-01-01

    Full Text Available An easy and fast gel diffusion assay for detecting and monitoring lipase activity by quantification of fluorescein is described. By measuring the intensity of fluorescein, it is possible to obtain a calibration curve with a regression coefficient better than by using the radius of fluorescent haloes. Through the quantification of fluorescence intensity of fluorescein released after the hydrolysis of a fluorescent ester, fluorescein dibutyrate, used as substrate in agar plates, commercial and skimmed milk lipase activity were studied. Moreover, with this method, lipase activity can be monitored in reaction medium that contains compounds which are affected by turbidity or cause measurement interference for UV-spectrophotometer and fluorimeter. In this experiment, boiled skimmed milk was dispersed in the agar gel with fluorescein dibutyrate, and it was used as a reaction medium to mimic natural conditions. The development of such an assay has a potential for applications in industries ranging from pharmaceuticals to food production and monitoring.

  18. Jet energy calibration in ATLAS

    CERN Document Server

    Schouten, Doug

    A correct energy calibration for jets is essential to the success of the ATLAS experi- ment. In this thesis I study a method for deriving an in situ jet energy calibration for the ATLAS detector. In particular, I show the applicability of the missing transverse energy projection fraction method. This method is shown to set the correct mean energy for jets. Pileup effects due to the high luminosities at ATLAS are also stud- ied. I study the correlations in lateral distributions of pileup energy, as well as the luminosity dependence of the in situ calibration metho

  19. Lateral flow assays.

    Science.gov (United States)

    Koczula, Katarzyna M; Gallotta, Andrea

    2016-06-30

    Lateral flow assays (LFAs) are the technology behind low-cost, simple, rapid and portable detection devices popular in biomedicine, agriculture, food and environmental sciences. This review presents an overview of the principle of the method and the critical components of the assay, focusing on lateral flow immunoassays. This type of assay has recently attracted considerable interest because of its potential to provide instantaneous diagnosis directly to patients. The range and interpretation of results and parameters used for evaluation of the assay will also be discussed. The main advantages and disadvantages of LFAs will be summarized and relevant future improvements to testing devices and strategies will be proposed. Finally, the major recent advances and future diagnostic applications in the LFA field will be explored. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  20. Lateral flow assays

    Science.gov (United States)

    Koczula, Katarzyna M.

    2016-01-01

    Lateral flow assays (LFAs) are the technology behind low-cost, simple, rapid and portable detection devices popular in biomedicine, agriculture, food and environmental sciences. This review presents an overview of the principle of the method and the critical components of the assay, focusing on lateral flow immunoassays. This type of assay has recently attracted considerable interest because of its potential to provide instantaneous diagnosis directly to patients. The range and interpretation of results and parameters used for evaluation of the assay will also be discussed. The main advantages and disadvantages of LFAs will be summarized and relevant future improvements to testing devices and strategies will be proposed. Finally, the major recent advances and future diagnostic applications in the LFA field will be explored. PMID:27365041

  1. Tube-Forming Assays.

    Science.gov (United States)

    Brown, Ryan M; Meah, Christopher J; Heath, Victoria L; Styles, Iain B; Bicknell, Roy

    2016-01-01

    Angiogenesis involves the generation of new blood vessels from the existing vasculature and is dependent on many growth factors and signaling events. In vivo angiogenesis is dynamic and complex, meaning assays are commonly utilized to explore specific targets for research into this area. Tube-forming assays offer an excellent overview of the molecular processes in angiogenesis. The Matrigel tube forming assay is a simple-to-implement but powerful tool for identifying biomolecules involved in angiogenesis. A detailed experimental protocol on the implementation of the assay is described in conjunction with an in-depth review of methods that can be applied to the analysis of the tube formation. In addition, an ImageJ plug-in is presented which allows automatic quantification of tube images reducing analysis times while removing user bias and subjectivity.

  2. Modelling the comet assay.

    Science.gov (United States)

    McArt, Darragh G; McKerr, George; Howard, C Vyvyan; Saetzler, Kurt; Wasson, Gillian R

    2009-08-01

    The single-cell gel electrophoresis technique or comet assay is widely regarded as a quick and reliable method of analysing DNA damage in individual cells. It has a proven track record from the fields of biomonitoring to nutritional studies. The assay operates by subjecting cells that are fixed in agarose to high salt and detergent lysis, thus removing all the cellular content except the DNA. By relaxing the DNA in an alkaline buffer, strands containing breaks are released from supercoiling. Upon electrophoresis, these strands are pulled out into the agarose, forming a tail which, when stained with a fluorescent dye, can be analysed by fluorescence microscopy. The intensity of this tail reflects the amount of DNA damage sustained. Despite being such an established and widely used assay, there are still many aspects of the comet assay which are not fully understood. The present review looks at how the comet assay is being used, and highlights some of its limitations. The protocol itself varies among laboratories, so results from similar studies may vary. Given such discrepancies, it would be attractive to break the assay into components to generate a mathematical model to investigate specific parameters.

  3. Optimization of the T-cell proliferation assay in fascioliasis using a ...

    African Journals Online (AJOL)

    T-cell proliferation studies are traditionally carried out with radioactive reagents or fluorescent reagents that require measurement with advanced technology instrumentation. We attempted to calibrate the optimal conditions suitable for the use of a non-radioactive assay for the measurement of a T-cell proliferation assay in ...

  4. Calibration of "Babyline" RP instruments

    CERN Multimedia

    2015-01-01

      If you have old RP instrumentation of the “Babyline” type, as shown in the photo, please contact the Radiation Protection Group (Joffrey Germa, 73171) to have the instrument checked and calibrated. Thank you. Radiation Protection Group

  5. Field calibration of cup anemometers

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, L.; Jensen, G.; Hansen, A.; Kirkegaard, P.

    2001-01-01

    An outdoor calibration facility for cup anemometers, where the signals from 10 anemometers of which at least one is a reference can be recorded simultaneously, has been established. The results are discussed with special emphasis on the statistical significance of the calibration expressions. It is concluded that the method has the advantage that many anemometers can be calibrated accurately with a minimum of work and cost. The obvious disadvantage is that the calibration of a set of anemometers may take more than one month in order to have wind speeds covering a sufficiently large magnitude range in a wind direction sector where we can be sure that the instruments are exposed to identical, simultaneous wind flows. Another main conclusion is that statistical uncertainty must be carefully evaluated since the individual 10 minute wind-speed averages are not statistically independent. (au)

  6. MAVEN SWEA Calibrated Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains fully calibrated electron energy/angle (3D) distributions, pitch angle distributions, and omni-directional energy spectra. Tables of sensitivity...

  7. MAVEN LPW Calibrated Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains fully calibrated, science quality data produced by the LPW instrument. The data include spacecraft potential, electric field waveforms and wave...

  8. Pressures Detector Calibration and Measurement

    CERN Document Server

    AUTHOR|(CDS)2156315

    2016-01-01

    This is report of my first and second projects (of 3) in NA61. I did data taking and analysis in order to do calibration of pressure detectors and verified it. I analyzed the data by ROOT software using the C ++ programming language. The first part of my project was determination of calibration factor of pressure sensors. Based on that result, I examined the relation between pressure drop, gas flow rate of in paper filter and its diameter.

  9. Beam Imaging and Luminosity Calibration

    CERN Document Server

    AUTHOR|(CDS)2081126; Klute, Markus; Medlock, Catherine Aiko

    2016-01-01

    We discuss a method to reconstruct two-dimensional proton bunch densities using vertex distributions accumulated during LHC beam-beam scans. The x-y correlations in the beam shapes are studied and an alternative luminosity calibration technique is introduced. We demonstrate the method on simulated beam-beam scans and estimate the uncertainty on the luminosity calibration associated to the beam-shape reconstruction to be below 1%.

  10. Identity, Diversity and Diversity Management

    DEFF Research Database (Denmark)

    Holck, Lotte; Muhr, Sara Louise; Villeseche, Florence

    2016-01-01

    The purpose of this paper is to examine the relationship between the identity and diversity literatures and discuss how a better understanding of the theoretical connections between the two informs both diversity research and diversity management practices. Design/methodology/approach – Literature...... review followed by a discussion of the theoretical and practical consequences of connecting the identity and diversity literatures. Findings – The authors inform future research in three ways. First, by showing how definitions of identity influence diversity theorizing in specific ways. Second...... and limitations – is crucial for successful diversity management research and practice. Research limitations/implications – The authors argue for a better understanding of differences, overlaps and limits of different identity perspectives, and for a stronger engagement with practice. Practical implications...

  11. Diversity Management

    DEFF Research Database (Denmark)

    Ravazzani, Silvia

    2018-01-01

    This entry provides an overview of diversity management which, in the context of organizations, consists in the strategic process of harnessing the potential of all employees to create an inclusive environment and, at the same time, contribute to meeting organizational goals. The entry first...... describes the complex construct of diversity that has been variously conceptualized in the literature, embracing multiple social and informational diversity dimensions such as gender, age, culture, values, and workstyle. This is followed by illustration of the historical development of diversity-management...... discourse and practice, and possible overarching approaches guiding organizations. It goes on to elucidate elements linked to the implementation of diversity management: positive and negative outcomes, most spread practices including communication, and contingency factors shaping the understanding...

  12. Mathematical calibration of Ge detectors, and the instruments that use them

    Energy Technology Data Exchange (ETDEWEB)

    Bronson, F.L.; Young, B. [Canberra Industries, Meriden, CT (United States)

    1997-11-01

    Efficiency calibrations for Ge detectors are typically done with the use of multiple energy calibrations sources which are added to a bulk matrix intended to simulate the measurement sample, and then deposited in the sample container. This is rather easy for common laboratory samples. Bu, even there, for many environmental samples, waste assay samples, and operational health physics samples, accurate calibrations are difficult. For these situations, various mathematical corrections or direct calibration techniques are used at Canberra. EML has pioneered the use of mathematical calibrations following source-based detector characterization measurements for in situ measurements of environmental fallout. Canberra has expanded this by the use of MCNP for the source measurements required in EML. For other calibration situations, MCNP was used directly, as the primary calibration method. This is demonstrated to be at least as accurate as source based measurements, and probably better. Recently, a new method [ISOCS] has been developed and is nearing completion. This promises to be an easy to use calibration software that can be used by the customer for in situ gamma spectroscopy to accurately measure many large sized samples, such as boxes, drums, pipes, or to calibrate small laboratory-type samples. 8 refs., 8 figs., 5 tabs.

  13. Lateral flow strip assay

    Science.gov (United States)

    Miles, Robin R [Danville, CA; Benett, William J [Livermore, CA; Coleman, Matthew A [Oakland, CA; Pearson, Francesca S [Livermore, CA; Nasarabadi, Shanavaz L [Livermore, CA

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  14. 21 CFR 868.6400 - Calibration gas.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calibration gas. 868.6400 Section 868.6400 Food... DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6400 Calibration gas. (a) Identification. A calibration gas is a device consisting of a container of gas of known concentration intended to calibrate medical...

  15. Calibration of the SNO+ experiment

    Science.gov (United States)

    Maneira, J.; Falk, E.; Leming, E.; Peeters, S.; SNO+ Collaboration.

    2017-09-01

    The main goal of the SNO+ experiment is to perform a low-background and high-isotope-mass search for neutrinoless double-beta decay, employing 780 tonnes of liquid scintillator loaded with tellurium, in its initial phase at 0.5% by mass for a total mass of 1330 kg of 130Te. The SNO+ physics program includes also measurements of geo- and reactor neutrinos, supernova and solar neutrinos. Calibrations are an essential component of the SNO+ data-taking and analysis plan. The achievement of the physics goals requires both an extensive and regular calibration. This serves several goals: the measurement of several detector parameters, the validation of the simulation model and the constraint of systematic uncertainties on the reconstruction and particle identification algorithms. SNO+ faces stringent radiopurity requirements which, in turn, largely determine the materials selection, sealing and overall design of both the sources and deployment systems. In fact, to avoid frequent access to the inner volume of the detector, several permanent optical calibration systems have been developed and installed outside that volume. At the same time, the calibration source internal deployment system was re-designed as a fully sealed system, with more stringent material selection, but following the same working principle as the system used in SNO. This poster described the overall SNO+ calibration strategy, discussed the several new and innovative sources, both optical and radioactive, and covered the developments on source deployment systems.

  16. Calibration techniques for fringe projectors

    Science.gov (United States)

    Peters, Joerg; Patzelt, Stefan; Horn, Frank; Goch, Gert

    2001-10-01

    Fringe Projection systems generate phase distributions of an object illuminated with a specific fringe pattern. These phase correspond to the object coordinates. It is mostly necessary to transform the dimension-less phases to a metric dimension. Until today this is realized by photogrammetric techniques, which are subdivided into three main processes. At first a reference plane is defined. Then a grid within this plane is fixed. In the third step, the height axis is calibrated by different methods, for example, by use of a single height step or another well defined base object. This article describes a new method to calibrate the measuring volume by a multi-value calibration algorithm. As a first step, the fringe projection systems detects the phase distribution of a plane, denoted as reference plane. The, the plane moves stepwise in z-direction. In each step the phase distribution is detected, while an interferometer measures the distance of the z-coordinate form the reference plane. Together with the discrete x-y-coordinates of a CCD- detection unit, a 3D measuring volume is defined. The volume calibration is performed by separate polynomials for each x- y-coordinate, which are derived from the corresponding values of the phase distributions and the interferometric height values. With this method some problems of the conventional 'single value calibration' can be solved. This contribution describes the theoretical solution of the problem and presents first experimental results.

  17. Gender Diversities

    DEFF Research Database (Denmark)

    Agustin, Lise Rolandsen; Siim, Birte

    2014-01-01

    The article analyses the European Year for Combating Poverty and Social Exclusion (2010) (EY 2010) with the aim of identifying the nature of gender diversities in EU policies. We argue that the EU handles issues related to gender and diversity in particular ways; this approach is characterized...... by non-citizen/citizen and redistribution/recognition divisions. Employing intersectionality as the methodological approach to gender diversities, the article shows how gender and ethnicity are articulated in the policy-making process which led to the adoption of EY 201, the activities undertaken during...... the EY 2010, and the evaluation of EY 2010. The case study is suitable for developing a dynamic multi-level model for analysing gendered diversities at the transnationmal level: It illustrates how the EU policy frame interacts with particular national contexts in promoting or hundering the advancement...

  18. Ecological diversity

    National Research Council Canada - National Science Library

    Pielou E. C

    1975-01-01

    The richness and variety-in a word, the diversity-of natural ecological communities have never been more highly valued than they are now, as they become increasingly threatened by the environmental crisis...

  19. Understanding Diversity

    NARCIS (Netherlands)

    D.L. van Knippenberg (Daan)

    2007-01-01

    textabstractDaan van Knippenberg is Professor of Organizational Behavior at RSM Erasmus University, Erasmus University Rotterdam, The Netherlands. His research interests include work group performance, especially work group diversity and group decision making, leadership, in particular the roles of

  20. Method of assaying uranium with prompt fission and thermal neutron borehole logging adjusted by borehole physical characteristics

    Science.gov (United States)

    Barnard, Ralston W.; Jensen, Dal H.

    1982-01-01

    Uranium formations are assayed by prompt fission neutron logging techniques. The uranium in the formation is proportional to the ratio of epithermal counts to thermal or eqithermal dieaway. Various calibration factors enhance the accuracy of the measurement.

  1. Method of assaying uranium with prompt fission and thermal neutron borehole logging adjusted by borehole physical characteristics. [Patient application

    Science.gov (United States)

    Barnard, R.W.; Jensen, D.H.

    1980-11-05

    Uranium formations are assayed by prompt fission neutron logging techniques. The uranium in the formation is proportional to the ratio of epithermal counts to thermal or epithermal dieaway. Various calibration factors enhance the accuracy of the measurement.

  2. (MTT) dye reduction assay.

    African Journals Online (AJOL)

    to inhibit proliferation of HeLa cells was determined using the 3443- dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) dye reduction assay. Extracts from roots of Agathisanthemum bojeri, Synaptolepis kirkii and Zanha africana and the leaf extract of Physalis peruviana at a concentration of 10 pg/ml inhibited cell ...

  3. Hyaluronic Acid Assays

    DEFF Research Database (Denmark)

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H

    2015-01-01

    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  4. Astrid-2 EMMA Magnetic Calibration

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Risbo, Torben

    1998-01-01

    of the magnetometer readings in each position were related to the field magnitudes from the Observatory, and a least squares fit for the 9 magnetometer calibration parameters was performed (3 offsets, 3 scale values and 3 inter-axes angles). After corrections for the magnetometer digital-to-analogue converters...... experiment built as a collaboration between the DTU, Department of Automation and the Department of Plasma Physics, The Alfvenlaboratory, Royal Institute of Technology (RIT), Stockholm. The final magnetic calibration of the Astrid-2 satellite was done at the Lovoe Magnetic Observatory under the Geological...... Survey of Sweden near Stockholm on the night of May 15.-16., 1997. The magnetic calibration and the intercalibration between the star camera and the magnetic sensor was performed by measuring the Earth's magnetic field and simultaneously observing the star sky with the camera. The rotation matrix between...

  5. Reliability-Based Code Calibration

    DEFF Research Database (Denmark)

    Faber, M.H.; Sørensen, John Dalsgaard

    2003-01-01

    The present paper addresses fundamental concepts of reliability based code calibration. First basic principles of structural reliability theory are introduced and it is shown how the results of FORM based reliability analysis may be related to partial safety factors and characteristic values....... Thereafter the code calibration problem is presented in its principal decision theoretical form and it is discussed how acceptable levels of failure probability (or target reliabilities) may be established. Furthermore suggested values for acceptable annual failure probabilities are given for ultimate...... and serviceability limit states. Finally the paper describes the Joint Committee on Structural Safety (JCSS) recommended procedure - CodeCal - for the practical implementation of reliability based code calibration of LRFD based design codes....

  6. Paraprotein interference with turbidimetric gentamicin assay.

    Science.gov (United States)

    Dimeski, Goce; Bassett, Kendra; Brown, Nigel

    2015-01-01

    Gentamicin due to its low level of resistance and rapid bactericidal activity is commonly used to treat gram-negative bacteria. However, due to its toxic effects it needs to be monitored. To date, no interference has been reported with gentamicin assays. A patient with leg cellulitis and sepsis received a single dose of gentamicin and a sample was sent for gentamicin analysis. The sample showed high blank absorbance readings on Beckman DxC800 and DC800 analysers with various dilutions. A second sample was received and analysed on a Roche Cobas system to obtain a result. A third sample was received 107 hours later with the same results and this sample was then analysed neat and post ethanol precipitation on all the turbidimetric assays available on the DxC800 analyser. The high blank absorbance was observed upon addition of the reactive reagents due to protein precipitation. Although not obvious from the patient protein results, it was shown the presence of high IgM paraprotein, 18.9 g/L (reference range 0.4-2.3 g/L) was the cause of precipitation, giving high blank readings. Of all the other turbidimetric assays, only vancomicin and valproate showed similar high blank absorbance readings. To be able to provide more rapid results it was shown ethanol could be used as a precipitant of proteins in both calibrators and patient samples with acceptable recovery. IgM paraprotein was identified as the cause of interference with the gentamicin, vancomicin and valproate assays. Protein interference in these assays can be overcome by precipitation with ethanol.

  7. Improving quantitative precision and throughput by reducing calibrator use in liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rule, Geoffrey S., E-mail: geoffrey.s.rule@aruplab.com [ARUP Institute for Clinical and Experimental Pathology, 500 Chipeta Way, Salt Lake City, UT 84108 (United States); Rockwood, Alan L. [ARUP Institute for Clinical and Experimental Pathology, 500 Chipeta Way, Salt Lake City, UT 84108 (United States); Department of Pathology, University of Utah School of Medicine, 2100 Jones Medical Research Bldg., Salt Lake City, UT 84132 (United States)

    2016-05-05

    To improve efficiency in our mass spectrometry laboratories we have made efforts to reduce the number of calibration standards utilized for quantitation over time. We often analyze three or more batches of 96 samples per day, on a single instrument, for a number of assays. With a conventional calibration scheme at six concentration levels this amounts to more than 5000 calibration points per year. Modern LC-tandem mass spectrometric instrumentation is extremely rugged however, and isotopically labelled internal standards are widely available. This made us consider whether alternative calibration strategies could be utilized to reduce the number of calibration standards analyzed while still retaining high precision and accurate quantitation. Here we demonstrate how, by utilizing a single calibration point in each sample batch, and using the resulting response factor (RF) to update an existing, historical response factor (HRF), we are able to obtain improved precision over a conventional multipoint calibration approach, as judged by quality control samples. The laboratory component of this study was conducted with an existing LC tandem mass spectrometric method for three androgen analytes in our production laboratory. Using examples from both simulated and laboratory data we illustrate several aspects of our single point alternative calibration strategy and compare it with a conventional, multipoint calibration approach. We conclude that both the cost and burden of preparing multiple calibration standards with every batch of samples can be reduced while at the same time maintaining, or even improving, analytical quality. - Highlights: • Use of a weighted single point calibration approach improves quantitative precision. • A weighted response factor approach incorporates historical calibration information. • Several scenarios are discussed with regard to their influence on quantitation.

  8. Improved uncertainty quantification in nondestructive assay for nonproliferation

    Energy Technology Data Exchange (ETDEWEB)

    Burr, Tom; Croft, Stephen; Jarman, Ken; Nicholson, Andrew; Norman, Claude; Walsh, Stephen

    2016-12-01

    This paper illustrates methods to improve uncertainty quantification (UQ) for non-destructive assay (NDA) measurements used in nuclear nonproliferation. First, it is shown that current bottom-up UQ applied to calibration data is not always adequate, for three main reasons: (1) Because there are errors in both the predictors and the response, calibration involves a ratio of random quantities, and calibration data sets in NDA usually consist of only a modest number of samples (3–10); therefore, asymptotic approximations involving quantities needed for UQ such as means and variances are often not sufficiently accurate; (2) Common practice overlooks that calibration implies a partitioning of total error into random and systematic error, and (3) In many NDA applications, test items exhibit non-negligible departures in physical properties from calibration items, so model-based adjustments are used, but item-specific bias remains in some data. Therefore, improved bottom-up UQ using calibration data should predict the typical magnitude of item-specific bias, and the suggestion is to do so by including sources of item-specific bias in synthetic calibration data that is generated using a combination of modeling and real calibration data. Second, for measurements of the same nuclear material item by both the facility operator and international inspectors, current empirical (top-down) UQ is described for estimating operator and inspector systematic and random error variance components. A Bayesian alternative is introduced that easily accommodates constraints on variance components, and is more robust than current top-down methods to the underlying measurement error distributions.

  9. Performance standard for dose Calibrator

    CERN Document Server

    Darmawati, S

    2002-01-01

    Dose calibrator is an instrument used in hospitals to determine the activity of radionuclide for nuclear medicine purposes. International Electrotechnical Commission (IEC) has published IEC 1303:1994 standard that can be used as guidance to test the performance of the instrument. This paper briefly describes content of the document,as well as explains the assessment that had been carried out to test the instrument accuracy in Indonesia through intercomparison measurement.Its is suggested that hospitals acquire a medical physicist to perform the test for its dose calibrator. The need for performance standard in the form of Indonesia Standard is also touched.

  10. Model Calibration in Option Pricing

    Directory of Open Access Journals (Sweden)

    Andre Loerx

    2012-04-01

    Full Text Available We consider calibration problems for models of pricing derivatives which occur in mathematical finance. We discuss various approaches such as using stochastic differential equations or partial differential equations for the modeling process. We discuss the development in the past literature and give an outlook into modern approaches of modelling. Furthermore, we address important numerical issues in the valuation of options and likewise the calibration of these models. This leads to interesting problems in optimization, where, e.g., the use of adjoint equations or the choice of the parametrization for the model parameters play an important role.

  11. Instrument Calibration and Certification Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R. Wesley [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-05-31

    The Amptec 640SL-2 is a 4-wire Kelvin failsafe resistance meter, designed to reliably use very low-test currents for its resistance measurements. The 640SL-1 is a 2-wire version, designed to support customers using the Reynolds Industries type 311 connector. For both versions, a passive (analog) dual function DC Milliameter/Voltmeter allows the user to verify the actual 640SL output current level and the open circuit voltage on the test leads. This procedure includes tests of essential performance parameters. Any malfunction noticed during calibration, whether specifically tested for or not, shall be corrected before calibration continues or is completed.

  12. Tank calibration; Arqueacao de tanques

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Ana [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This work relates the analysis of the norms ISO (International Organization for Standardization) for calibration of vertical cylindrical tanks used in fiscal measurement, established on Joint Regulation no 1 of June 19, 2000 between the ANP (National Agency of Petroleum) and the INMETRO (National Institute of Metrology, Normalization and Industrial Quality). In this work a comparison between norms ISO and norms published by the API (American Petroleum Institute) and the IP (Institute of Petroleum) up to 2001 was made. It was concluded that norms ISO are wider than norms API, IP, and INMETRO methods in the calibration of vertical cylindrical tanks. (author)

  13. NIST display colorimeter calibration facility

    Science.gov (United States)

    Brown, Steven W.; Ohno, Yoshihiro

    2003-07-01

    A facility has been developed at the National Institute of Standards and Technology (NIST) to provide calibration services for color-measuring instruments to address the need for improving and certifying the measurement uncertainties of this type of instrument. While NIST has active programs in photometry, flat panel display metrology, and color and appearance measurements, these are the first services offered by NIST tailored to color-measuring instruments for displays. An overview of the facility, the calibration approach, and associated uncertainties are presented. Details of a new tunable colorimetric source and the development of new transfer standard instruments are discussed.

  14. A Subjectivist View of Calibration.

    Science.gov (United States)

    1982-07-01

    the predictions its staff makes about possible new drugs are well-calibrated proba- bilities (Balthasar, Boschi , & Menke, 1978). For the cognitive...under uncertainty: Heuristics and biases. New York: Cambridge University Press, 1982. Balthasar, H. A., Boschi , R. A. A., & Menke, M. M. Calling the

  15. Laboratory panel and radiometer calibration

    CSIR Research Space (South Africa)

    Deadman, AJ

    2011-07-01

    Full Text Available this is not possible, that a look-up table be created to correct 8?/hemispherical reflectance values. 6. REFERENCES [1] N.P. Fox ?QA4EO-WGCV-IVO-CLP-008: Protocol for the CEOS WGCV pilot Comparison of techniques/instruments used for vicarious calibration...

  16. Model Calibration for Ship Simulations

    NARCIS (Netherlands)

    E.F.G. van Daalen (Ed); J. Fehribach; T. van Leeuwen (Tristan); C. Reinhardt; N. Schenkels; R. Sheombarsing

    2014-01-01

    htmlabstractModel calibration is an important aspect in ship simulation. Here, ship motion is described by an ODE which includes tuning parameters that capture complex physical processes such as friction of the hull. In order for the simulations to be realistic for a wide range of

  17. Model Calibration for Ship Simulations

    NARCIS (Netherlands)

    van Daalen, Ed; Fehribach, Joseph; van Leeuwen, Tristan; Reinhardt, Christian; Schenkels, Nick; Sheombarsing, Ray

    2014-01-01

    Model calibration is an important aspect in ship simulation. Here, ship motion is described by an ODE which includes tuning parameters that capture complex physical processes such as friction of the hull. In order for the simulations to be realistic for a wide range of scenarios these tuning

  18. Recommended Inorganic Chemicals for Calibration.

    Science.gov (United States)

    Moody, John R.; And Others

    1988-01-01

    All analytical techniques depend on the use of calibration chemicals to relate analyte concentration to instrumental parameters. Discusses the preparation of standard solutions and provides a critical evaluation of available materials. Lists elements by group and discusses the purity and uses of each. (MVL)

  19. Measurement System and Calibration report

    DEFF Research Database (Denmark)

    Vesth, Allan; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  20. Measurement System and Calibration report

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Villanueva, Héctor

    This Measurement System & Calibration report is describing DTU’s measurement system installed at a specific wind turbine. A major part of the sensors has been installed by others (see [1]) the rest of the sensors have been installed by DTU. The results of the measurements, described in this repor...

  1. Global assays of fibrinolysis.

    Science.gov (United States)

    Ilich, A; Bokarev, I; Key, N S

    2017-10-01

    Fibrinolysis is an important and integral part of the hemostatic system. Acting as a balance to blood coagulation, the fibrinolytic system protects the body from unwanted thrombus formation and occlusion of blood vessels. As long as blood coagulation and fibrinolysis remain in equilibrium, response to injury, such as vessel damage, is appropriately regulated. However, alterations in this balance may lead to thrombosis or bleeding. A variety of methods have been proposed to assess fibrinolytic activity in blood or its components, but due to the complexity of the system, the design of a "gold standard" assay that reflects overall fibrinolysis has remained an elusive goal. In this review, we describe the most commonly used methods that have been described, such as thromboelastography (TEG and ROTEM), global fibrinolytic capacity in plasma and whole blood, plasma turbidity methods, simultaneous thrombin and plasmin generation assays, euglobulin clot lysis time and fibrin plate methods. All of these assays have strengths and limitations. We suggest that some methods may be preferable for detecting hypofibrinolytic conditions, whereas others may be better for detecting hyperfibrinolytic states. © 2017 John Wiley & Sons Ltd.

  2. Calibration Report for the WRAP Facility Gamma Energy Analysis System [104-ND-06-102A

    Energy Technology Data Exchange (ETDEWEB)

    WILLS, C.E.

    2000-02-15

    The Waste Receiving And Processing facility (WRAP) adheres to providing gamma-ray spectroscopy instrument calibrations traceable to the National Institute for Standards and Technology (NIST) standards. The detectors are used to produce quantitative results for the Waste Isolation Pilot Plant (WIPP) and must meet calibration programmatic calibration goals. Instruments must meet portions of ANSI N42.14, 1978 guide for Germanium detectors. The Non-Destructive Assay (NDA) Gamma Energy Analysis (GEA) utilizes NIST traceable line source standards for the detector system calibrations. The counting configuration is a series of drums containing the line sources and different density filler matrices. The drums are used to develop system efficiencies with respect to density. The efficiency and density correction factors are required for the processing of drummed waste materials of similar densities. The calibration verification is carried out after the calibration is deemed final, by counting a second drum of NIST traceable sources. Three in-depth calibrations have been completed on one of the two systems to date, the first being the system acceptance plan. This report has a secondary function; that being the development of the instrument calibration errors which are to be folded into the Total Instrument Uncertainty document, HNF-4050.

  3. Mathematical efficiency calibration in gamma spectroscopy

    CERN Document Server

    Kaminski, S; Wilhelm, C

    2003-01-01

    Mathematical efficiency calibration with the LabSOCS software was introduced for two detectors in the measurement laboratory of the Central Safety Department of Forschungszentrum Karlsruhe. In the present contribution, conventional efficiency calibration of gamma spectroscopy systems and mathematical efficiency calibration with LabSOCS are compared with respect to their performance, uncertainties, expenses, and results. It is reported about the experience gained, and the advantages and disadvantages of both methods of efficiency calibration are listed. The results allow the conclusion to be drawn that mathematical efficiency calibration is a real alternative to conventional efficiency calibration of gamma spectroscopy systems as obtained by measurements of mixed gamma ray standard sources.

  4. Abbott ARCHITECT iPhenytoin assay versus similar assays for measuring free phenytoin concentrations.

    Science.gov (United States)

    Tacker, Danyel Hermes; Robinson, Randy; Perrotta, Peter L

    2014-01-01

    To measure free phenytoin (FP) concentrations in filtered specimens using the Abbott ARCHITECT iPhenytoin assay and to compare results from this method with results from the Abbott TDx/FLx assays. We verified accuracy, analytic measurement range, and precision for FP measurements. For correlation and therapeutic interval studies, we used filtered calibrators, controls, proficiency-testing materials, and surplus clinical samples. After implementation, we determined proficiency testing results. The analytic measurement range was 2.0 to 25.0 micromol/L. Quality control materials (6.1, 12.6, and 20.1 micromol/L) provided mean (SD) recoveries of 96.1 (5.0%), 99.2 (5.0%), and 99.3 (5.7%), respectively, and coefficients of variation of 5.2%, 5.0%, and 5.8%, respectively. Clinical specimens produced mean (SD) FP recovery levels of 103.7 (10.6%) (bias, 0.1 [0.3] micromol/L). Altering the FP therapeutic range (4.0-8.0 micromol/L) was unnecessary. Proficiency testing yielded consistently acceptable results. Our accuracy, precision, and correlation results were similar for the TDx/FLx and ARCHITECT assays, which demonstrates that the ARCHITECT iPhenytoin assay is acceptable for clinical FP measurements.

  5. Nondestructive assay needs at the Los Alamos Plutonium Facility

    Energy Technology Data Exchange (ETDEWEB)

    Cremesa, T.L.; Longmire, V.L. [Los Alamos National Laboratory, NM (United States)

    1993-12-31

    The Los Alamos National Laboratory Plutonium Facility is the leading facility for research and development in the area of plutonium processing. The diverse aspects of the activities at this facility require a large and varied effort in the area of non-destructive assay (NDA). The NDA activities at the plutonium facility fall into three different categories: accountability, safeguards, and process control. This talk will describe assay methods, instruments, and future needs and directions of NDA at the plutonium facility.

  6. Diverse Multilateralism

    DEFF Research Database (Denmark)

    Wuthnow, Joel; Li, Xin; Qi, Lingling

    2012-01-01

    in both the economic and security domains, the article argues that China’s multilateralism is diverse, and that it cannot be un-problematically characterized as either status-quo or revisionist in nature. However, the general trend appears to be towards engagement, but with an assertive tact as China...

  7. Generational diversity.

    Science.gov (United States)

    Kramer, Linda W

    2010-01-01

    Generational diversity has proven challenges for nurse leaders, and generational values may influence ideas about work and career planning. This article discusses generational gaps, influencing factors and support, and the various generational groups present in today's workplace as well as the consequences of need addressing these issues. The article ends with a discussion of possible solutions.

  8. Discovering Diversity.

    Science.gov (United States)

    Manner, Barbara M.; Hattler, Jean Anne

    2000-01-01

    Introduces a preservice teacher field trip to the rain forests and coastal areas. This experience develops an awareness for different cultures among preservice teachers by experiencing biological and cultural diversity in Costa Rica. Presents students' own ideas on this experience. (YDS)

  9. Representative Diversity.

    Science.gov (United States)

    Jacklin, Phil

    1978-01-01

    Presents eight propositions for different kinds of diversity, in order of importance, based on relevance to democracy; specifically, relevance to openness in the marketplace of ideas, and to creation of the system of communications which is least restrictive of freedom of speech and of the press. (JMF)

  10. CATE 2016 Indonesia: Image Calibration, Intensity Calibration, and Drift Scan

    Science.gov (United States)

    Hare, H. S.; Kovac, S. A.; Jensen, L.; McKay, M. A.; Bosh, R.; Watson, Z.; Mitchell, A. M.; Penn, M. J.

    2016-12-01

    The citizen Continental America Telescopic Eclipse (CATE) experiment aims to provide equipment for 60 sites across the path of totality for the United States August 21st, 2017 total solar eclipse. The opportunity to gather ninety minutes of continuous images of the solar corona is unmatched by any other previous eclipse event. In March of 2016, 5 teams were sent to Indonesia to test CATE equipment and procedures on the March 9th, 2016 total solar eclipse. Also, a goal of the trip was practice and gathering data to use in testing data reduction methods. Of the five teams, four collected data. While in Indonesia, each group participated in community outreach in the location of their site. The 2016 eclipse allowed CATE to test the calibration techniques for the 2017 eclipse. Calibration dark current and flat field images were collected to remove variation across the cameras. Drift scan observations provided information to rotationally align the images from each site. These image's intensity values allowed for intensity calibration for each of the sites. A GPS at each site corrected for major computer errors in time measurement of images. Further refinement of these processes is required before the 2017 eclipse. This work was made possible through the NSO Training for the 2017 Citizen CATE Experiment funded by NASA (NASA NNX16AB92A).

  11. Stable isotope dilution assays in mycotoxin analysis.

    Science.gov (United States)

    Rychlik, Michael; Asam, Stefan

    2008-01-01

    The principle and applications of stable isotope dilution assays (SIDAs) in mycotoxin analysis are critically reviewed. The general section includes historical aspects of SIDAs, the prerequisites and limitations of the use of stable isotopically labelled internal standards, and possible calibration procedures. In the application section actual SIDAs for the analysis of trichothecenes, zearalenone, fumonisins, patulin, and ochratoxin A are presented. The syntheses and availability of labelled mycotoxins for use as internal standards is reviewed and specific advances in food analysis and toxicology are demonstrated. The review indicates that LC-MS applications, in particular, require the use of stable isotopically labelled standards to compensate for losses during clean-up and for discrimination due to ion suppression. As the commercial availability of these compounds continues to increase, SIDAs can be expected to find expanding use in mycotoxin analysis.

  12. Stable isotope dilution assays in mycotoxin analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rychlik, Michael; Asam, Stefan [Universitaet Muenchen, Lehrstuhl fuer Lebensmittelchemie der Technischen, Garching (Germany)

    2008-01-15

    The principle and applications of stable isotope dilution assays (SIDAs) in mycotoxin analysis are critically reviewed. The general section includes historical aspects of SIDAs, the prerequisites and limitations of the use of stable isotopically labelled internal standards, and possible calibration procedures. In the application section actual SIDAs for the analysis of trichothecenes, zearalenone, fumonisins, patulin, and ochratoxin A are presented. The syntheses and availability of labelled mycotoxins for use as internal standards is reviewed and specific advances in food analysis and toxicology are demonstrated. The review indicates that LC-MS applications, in particular, require the use of stable isotopically labelled standards to compensate for losses during clean-up and for discrimination due to ion suppression. As the commercial availability of these compounds continues to increase, SIDAs can be expected to find expanding use in mycotoxin analysis. (orig.)

  13. SMAP RADAR Calibration and Validation

    Science.gov (United States)

    West, R. D.; Jaruwatanadilok, S.; Chaubel, M. J.; Spencer, M.; Chan, S. F.; Chen, C. W.; Fore, A.

    2015-12-01

    The Soil Moisture Active Passive (SMAP) mission launched on Jan 31, 2015. The mission employs L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Immediately following launch, there was a three month instrument checkout period, followed by six months of level 1 (L1) calibration and validation. In this presentation, we will discuss the calibration and validation activities and results for the L1 radar data. Early SMAP radar data were used to check commanded timing parameters, and to work out issues in the low- and high-resolution radar processors. From April 3-13 the radar collected receive only mode data to conduct a survey of RFI sources. Analysis of the RFI environment led to a preferred operating frequency. The RFI survey data were also used to validate noise subtraction and scaling operations in the radar processors. Normal radar operations resumed on April 13. All radar data were examined closely for image quality and calibration issues which led to improvements in the radar data products for the beta release at the end of July. Radar data were used to determine and correct for small biases in the reported spacecraft attitude. Geo-location was validated against coastline positions and the known positions of corner reflectors. Residual errors at the time of the beta release are about 350 m. Intra-swath biases in the high-resolution backscatter images are reduced to less than 0.3 dB for all polarizations. Radiometric cross-calibration with Aquarius was performed using areas of the Amazon rain forest. Cross-calibration was also examined using ocean data from the low-resolution processor and comparing with the Aquarius wind model function. Using all a-priori calibration constants provided good results with co-polarized measurements matching to better than 1 dB, and cross-polarized measurements matching to about 1 dB in the beta release. During the

  14. Radon assay for SNO+

    Energy Technology Data Exchange (ETDEWEB)

    Rumleskie, Janet [Laurentian University, Greater Sudbury, Ontario (Canada)

    2015-12-31

    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

  15. Crop physiology calibration in the CLM

    Directory of Open Access Journals (Sweden)

    I. Bilionis

    2015-04-01

    scalable and adaptive scheme based on sequential Monte Carlo (SMC. The model showed significant improvement of crop productivity with the new calibrated parameters. We demonstrate that the calibrated parameters are applicable across alternative years and different sites.

  16. Polarimetric and Interferometric SAR Calibration Verification Methods

    Science.gov (United States)

    Kim, Y.; Zyl, J van

    2001-01-01

    It is necessary to calibrate SAR data in order to use the data for science applications. When both polarimetric and interferometric data are collected simultaneously, these SAR data can be used for cross-calibration and verification.

  17. NIR calibration of soluble stem carbohydrates for predicting drought tolerance in spring wheat

    Science.gov (United States)

    Soluble stem carbohydrates are a component of drought response in wheat (Triticum aestivum L.) and other grasses. Near-infrared spectroscopy (NIR) can rapidly assay for soluble carbohydrates indirectly, but this requires a statistical model for calibration. The objectives of this study were: (i) to ...

  18. Scalar Calibration of Vector Magnetometers

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz

    2000-01-01

    The calibration parameters of a vector magnetometer are estimated only by the use of a scalar reference magnetometer. The method presented in this paper differs from those previously reported in its linearized parametrization. This allows the determination of three offsets or signals in the absence...... of a magnetic field, three scale factors for normalization of the axes and three non-orthogonality angles which build up an orthogonal system intrinsically in the sensor. The advantage of this method compared with others lies in its linear least squares estimator, which finds independently and uniquely...... the parameters for a given data set. Therefore, a magnetometer may be characterized inexpensively in the Earth's magnetic-field environment. This procedure has been used successfully in the pre-flight calibration of the state-of-the-art magnetometers on board the magnetic mapping satellites Orsted, Astrid-2...

  19. Local Hadron Calibration in Atlas.

    CERN Document Server

    Giovannini, P; The ATLAS collaboration

    2010-01-01

    The method of Local Hadron Calibration is used in Atlas as one of two major calibration schemes for hadronic signals like jets and missing transverse energy. Starting from noise suppressed energy clusters a modular chain of classification and corrections steps are applied to distinguish electro-magnetic from hadronic deposits and to compensate invisible energy losses, deposits in dead material and noise threshold related losses. Finally jet-level corrections take care of missing energy due to particles never reaching the calorimeter. The method and its application to single charged and neutral pion simulations as well as di-jet simulations are presented. First comparisons of MinBias simulations and real Atlas data at sqrt(s)=900 GeV are shown.

  20. Optimal Reliability-Based Code Calibration

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Kroon, I. B.; Faber, Michael Havbro

    1994-01-01

    Calibration of partial safety factors is considered in general, including classes of structures where no code exists beforehand. The partial safety factors are determined such that the difference between the reliability for the different structures in the class considered and a target reliability...... level is minimized. Code calibration on a decision theoretical basis is also considered and it is shown how target reliability indices can be calibrated. Results from code calibration for rubble mound breakwater designs are shown....

  1. Cross-calibration of interferometric SAR data

    DEFF Research Database (Denmark)

    Dall, Jørgen

    2003-01-01

    Generation of digital elevation models from interferometric synthetic aperture radar (SAR) data is a well established technique. Achieving a high geometric fidelity calls for a calibration accounting for inaccurate navigation data and system parameters as well as system imperfections. Fully...... automated calibration techniques are preferable, especially for operational mapping. The author presents one such technique, called cross-calibration. Though developed for single-pass interferometry, it may be applicable to multi-pass interferometry, too. Cross-calibration requires stability during mapping...

  2. Calibrating thermal behavior of electronics

    Science.gov (United States)

    Chainer, Timothy J.; Parida, Pritish R.; Schultz, Mark D.

    2016-05-31

    A method includes determining a relationship between indirect thermal data for a processor and a measured temperature associated with the processor, during a calibration process, obtaining the indirect thermal data for the processor during actual operation of the processor, and determining an actual significant temperature associated with the processor during the actual operation using the indirect thermal data for the processor during actual operation of the processor and the relationship.

  3. ABCs of DNA aptamer and related assay development.

    Science.gov (United States)

    Sharma, Tarun Kumar; Bruno, John G; Dhiman, Abhijeet

    This review is intended to guide the novice in aptamer research and development to understand virtually all of the aptamer development options and currently available assay modalities. Aptamer development topics range from discussions of basic and advanced versions of Systematic Evolution of Ligands by EXponential Enrichment (SELEX) and SELEX variations involving incorporation of exotic unnatural nucleotides to expand library diversity for even greater aptamer affinity and specificity to improved next generation methods of DNA sequencing, screening and tracking aptamer development throughout the SELEX process and characterization of lead aptamer candidates. Aptamer assay development topics include descriptions of various colorimetric and fluorescent assays in microplates or on membranes including homogeneous beacon and multiplexed Fluorescence Resonance Energy Transfer (FRET) assays. Finally, a discussion of the potential for marketing successful aptamer-based assays or test kits is included. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Model Calibration in Watershed Hydrology

    Science.gov (United States)

    Yilmaz, Koray K.; Vrugt, Jasper A.; Gupta, Hoshin V.; Sorooshian, Soroosh

    2009-01-01

    Hydrologic models use relatively simple mathematical equations to conceptualize and aggregate the complex, spatially distributed, and highly interrelated water, energy, and vegetation processes in a watershed. A consequence of process aggregation is that the model parameters often do not represent directly measurable entities and must, therefore, be estimated using measurements of the system inputs and outputs. During this process, known as model calibration, the parameters are adjusted so that the behavior of the model approximates, as closely and consistently as possible, the observed response of the hydrologic system over some historical period of time. This Chapter reviews the current state-of-the-art of model calibration in watershed hydrology with special emphasis on our own contributions in the last few decades. We discuss the historical background that has led to current perspectives, and review different approaches for manual and automatic single- and multi-objective parameter estimation. In particular, we highlight the recent developments in the calibration of distributed hydrologic models using parameter dimensionality reduction sampling, parameter regularization and parallel computing.

  5. Troubling Diversity?

    DEFF Research Database (Denmark)

    Jæger, Kirsten; Jensen, Annie Aarup

    2009-01-01

    are related to recent contributions to diversity management theory and intercultural communication theory, calling for a strengthened focus on the historical, political, and social dimensions of intercultural contact. In continuation of these trends, an alternative, theoretical framework......Focussing on the cultural encounter between nurses and ethnic minority patients in Danish hospitals, this paper presents the results of a comprehensive analysis of nursing discourses on cultural difference and intercultural contact. Articles from the Danish professional journal ‘The Nurse......', published in the period from 2000 to 2008, pertaining to cultural contact and intercultural understanding have been analyzed in order to uncover nurses' experience of ethnic and cultural diversity and the ways, in which these experiences challenge their cultural and professional expertise. Results...

  6. Optimal, Reliability-Based Code Calibration

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2002-01-01

    Reliability based code calibration is considered in this paper. It is described how the results of FORM based reliability analysis may be related to the partial safety factors and characteristic values. The code calibration problem is presented in a decision theoretical form and it is discussed how...... of reliability based code calibration of LRFD based design codes....

  7. Calibration and simulation of Heston model

    Directory of Open Access Journals (Sweden)

    Mrázek Milan

    2017-05-01

    Full Text Available We calibrate Heston stochastic volatility model to real market data using several optimization techniques. We compare both global and local optimizers for different weights showing remarkable differences even for data (DAX options from two consecutive days. We provide a novel calibration procedure that incorporates the usage of approximation formula and outperforms significantly other existing calibration methods.

  8. HCAL Calibration Status in Summer 2017

    CERN Document Server

    CMS Collaboration

    2017-01-01

    This note presents the status of the HCAL calibration in Summer 2017. In particular, results on the aging of the hadron endcap (HE) detector measured using the laser calibration system and the calibration of the hadron forward (HF) detector using electrons from Z boson decays are discussed.

  9. FLUIDICS DEVICE FOR ASSAY

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention...... is adapted to receive one or more replaceable solid support(s) (40) onto which chemical entities (41) are attached, said device comprising a base (1, 60, 80, 300, 400, 10, 70, 140, 20, 90, 120, 150, 30, 100), one or more inlet(s) (5), one or more outlet(s) (6). The base and the solid support (40) defines......, when operatively connected, one or more chambers (21) comprising the chemical entities (41), the inlet(s) (5) and outlet(s) (6) and chambers (21) being in fluid connection. The device further comprise means for providing differing chemical conditions in each chamber (21)....

  10. Testing and calibration of geodetic instruments

    Directory of Open Access Journals (Sweden)

    Marek Bajtala

    2007-06-01

    Full Text Available The problem of testing, verification and calibration of length-scales (electronic rangefinders and angle-scales (geodetic instruments. The calibration of coded levelling rods and the systemic calibration of digital levelling instruments. The calibration on linear comparative baseline in a terrain – the elaboration of measured data. The testing of universal measuring instruments in laboratory conditions - specific problems in testing of instruments with the passive reflection. Some knowledge about the calibration of horizontal circles of angle-measuring geodetic instruments.

  11. Muon Energy Calibration of the MINOS Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Miyagawa, Paul S. [Somerville College, Oxford (United Kingdom)

    2004-01-01

    MINOS is a long-baseline neutrino oscillation experiment designed to search for conclusive evidence of neutrino oscillations and to measure the oscillation parameters precisely. MINOS comprises two iron tracking calorimeters located at Fermilab and Soudan. The Calibration Detector at CERN is a third MINOS detector used as part of the detector response calibration programme. A correct energy calibration between these detectors is crucial for the accurate measurement of oscillation parameters. This thesis presents a calibration developed to produce a uniform response within a detector using cosmic muons. Reconstruction of tracks in cosmic ray data is discussed. This data is utilized to calculate calibration constants for each readout channel of the Calibration Detector. These constants have an average statistical error of 1.8%. The consistency of the constants is demonstrated both within a single run and between runs separated by a few days. Results are presented from applying the calibration to test beam particles measured by the Calibration Detector. The responses are calibrated to within 1.8% systematic error. The potential impact of the calibration on the measurement of oscillation parameters by MINOS is also investigated. Applying the calibration reduces the errors in the measured parameters by ~ 10%, which is equivalent to increasing the amount of data by 20%.

  12. Cell Proliferation and Cytotoxicity Assays.

    Science.gov (United States)

    Adan, Aysun; Kiraz, Yağmur; Baran, Yusuf

    Cell viability is defined as the number of healthy cells in a sample and proliferation of cells is a vital indicator for understanding the mechanisms in action of certain genes, proteins and pathways involved cell survival or death after exposing to toxic agents. Generally, methods used to determine viability are also common for the detection of cell proliferation. Cell cytotoxicity and proliferation assays are generally used for drug screening to detect whether the test molecules have effects on cell proliferation or display direct cytotoxic effects. Regardless of the type of cell-based assay being used, it is important to know how many viable cells are remaining at the end of the experiment. There are a variety of assay methods based on various cell functions such as enzyme activity, cell membrane permeability, cell adherence, ATP production, co-enzyme production, and nucleotide uptake activity. These methods could be basically classified into different categories: (I) dye exclusion methods such as trypan blue dye exclusion assay, (II) methods based on metabolic activity, (III) ATP assay, (IV) sulforhodamine B assay, (V) protease viability marker assay, (VI) clonogenic cell survival assay, (VII) DNA synthesis cell proliferation assays and (V) raman micro-spectroscopy. In order to choose the optimal viability assay, the cell type, applied culture conditions, and the specific questions being asked should be considered in detail. This particular review aims to provide an overview of common cell proliferation and cytotoxicity assays together with their own advantages and disadvantages, their methodologies, comparisons and intended purposes.

  13. Verification of L-band SAR calibration

    Science.gov (United States)

    Larson, R. W.; Jackson, P. L.; Kasischke, E.

    1985-01-01

    Absolute calibration of a digital L-band SAR system to an accuracy of better than 3 dB has been verified. This was accomplished with a calibration signal generator that produces the phase history of a point target. This signal relates calibration values to various SAR data sets. Values of radar cross-section (RCS) of reference reflectors were obtained using a derived calibration relationship for the L-band channel on the ERIM/CCRS X-C-L SAR system. Calibrated RCS values were compared to known RCS values of each reference reflector for verification and to obtain an error estimate. The calibration was based on the radar response to 21 calibrated reference reflectors.

  14. Camera calibration in photogrammetric practice, introduction

    Science.gov (United States)

    Kupfer, G.

    Laboratory, stellar and ground calibrations are developed to assess accuracy and reliability of photographic systems and their components. Calibration of photographic systems is based on analytic assessment systems and software and calibration of aerial images in close-range photogrammetry. Algorithms to obtain simultaneous calibration of photographic systems and aerial images are developed. System reproduction, film printing plate flatness, filter glass plane parallelism, and definition of image plane or image coordinate system are calibrated in laboratory with a visual procedure using goniometers, theodolites and lens/mirror systems. Stellar calibration with or without filters is influenced by emulsion sensitivity. Ground calibration is based on image measurement and geodetic observations. Economical application of the different procedures is assessed.

  15. Doing Diversity

    DEFF Research Database (Denmark)

    Just, Sine Nørholm; Christiansen, Tanja Juul

    2012-01-01

    Questions of agency in text–audience relations are less studied than other aspects of rhetorical agency. We suggest conceptualizing and analyzing the relationship between texts and audiences from the perspective of performativity, as it has been developed by Judith Butler. Thus, we argue that texts...... invite audiences to take up subject positions, understood as combinations of identity and agency. Danish diversity management rhetoric functions as an illustrative example; in analyzing this type of rhetoric we show how subjects are called into restrained positions of similarity/difference and thereby...

  16. A Simple Assay for Measuring Catalase Activity: A Visual Approach

    Science.gov (United States)

    Iwase, Tadayuki; Tajima, Akiko; Sugimoto, Shinya; Okuda, Ken-ichi; Hironaka, Ippei; Kamata, Yuko; Takada, Koji; Mizunoe, Yoshimitsu

    2013-01-01

    In this study, an assay that combines the ease and simplicity of the qualitative approach for measuring catalase activity was developed. The assay reagents comprised only hydrogen peroxide and Triton X-100. The enzyme-generated oxygen bubbles trapped by Triton X-100 were visualized as foam, whose height was estimated. A calibration plot using the defined unit of catalase activity yielded the best linear fit over a range of 20–300 units (U) (y = 0.3794x − 2.0909, r2 = 0.993). The assay precision and reproducibility at 100 U were 4.6% and 4.8%, respectively. The applicability of the assay for measuring the catalase activity of various samples was assessed using laboratory strains of Escherichia coli, catalase-deficient isogenic mutants, clinically isolated Shiga toxin-producing E. coli, and human cells. The assay generated reproducible results. In conclusion, this new assay can be used to measure the catalase activity of bacterial isolates and human cells. PMID:24170119

  17. Online examiner calibration across specialties.

    Science.gov (United States)

    Sturman, Nancy; Wong, Wai Yee; Turner, Jane; Allan, Chris

    2017-09-26

    Integrating undergraduate medical curricula horizontally across clinical medical specialties may be a more patient-centred and learner-centred approach than rotating students through specialty-specific teaching and assessment, but requires some interspecialty calibration of examiner judgements. Our aim was to evaluate the acceptability and feasibility of an online pilot of interdisciplinary examiner calibration. Fair clinical assessment is important to both medical students and clinical teachers METHODS: Clinical teachers were invited to rate video-recorded student objective structured clinical examination (OSCE) performances and join subsequent online discussions using the university's learning management system. Post-project survey free-text and Likert-scale participant responses were analysed to evaluate the acceptability of the pilot and to identify recommendations for improvement. Although 68 clinicians were recruited to participate, and there were 1599 hits on recordings and discussion threads, only 25 clinical teachers rated at least one student performance, and 18 posted at least one comment. Participants, including rural doctors, appeared to value the opportunity for interdisciplinary rating calibration and discussion. Although the asynchronous online format had advantages, especially for rural doctors, participants reported considerable IT challenges. Our findings suggest that fair clinical assessment is important to both medical students and clinical teachers. Interspecialty discussions about assessment may have the potential to enrich intraspecialty perspectives, enhance interspecialty engagement and collaboration, and improve the quality of clinical teacher assessment. Better alignment of university and hospital systems, a face to face component and other modifications may have enhanced clinician engagement with this project. Findings suggest that specialty assessment cultures and content expertise may not be barriers to pursuing more integrated

  18. SMAP RADAR Calibration and Validation

    Science.gov (United States)

    West, R. D.; Jaruwatanadilok, S.; Chaubel, J.

    2014-12-01

    The Soil Moisture Active Passive (SMAP) mission is planned to launch on Jan 8, 2015. The mission employs L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Immediately following launch, there will be a 3 month instrument checkout period, followed by 6 months of level 1 (L1) calibration and validation. In this presentation, we will discuss the plans and preparations for the calibration and validation of L1 radar data from SMAP. At the start of the L1 cal/val period, we will validate the operation of the instrument and of the ground processing using tools that look at readily identifiable surface features such as coast lines and corner reflectors. Geometric biases will be fit and removed. Radiometric cross-calibration with PALSAR and Aquarius will also be performed using target regions in the Amazon rain forest selected for their stability and uniformity. As the L1 cal/val period progresses, the performance of the automated short and long term calibration modules in ground processing will be tracked and verified using data from stable reference targets such as the wind corrected ocean and selected areas of rain forest that have shown good temporal stability. The performance of the radio frequency interference (RFI) removal algorithm will be validated by processing data with the algorithm turned on and off, and using different parameter settings. Additional information on the extent of RFI will be obtained from a special RFI survey conducted early in the L1 cal/val period. Radar transmissions are turned off during the RFI survey, and receive only data are collected over a variety of operating frequencies. The model based Faraday rotation corrections will also be checked during the L1 cal/val by comparing the model Faraday rotation with the measured Faraday rotation obtained by the SMAP Radiometer. This work is supported by the SMAP project at the Jet

  19. Calibration of TOB+ Thermometer's Cards

    CERN Document Server

    Banitt, Daniel

    2014-01-01

    Motivation - Under the new upgrade of the CMS detector the working temperature of the trackers had been reduced to -27 Celsius degrees. Though the thermal sensors themselves (Murata and Fenwal thermistors) are effective at these temperatures, the max1542 PLC (programmable logic controller) cards, interpreting the resistance of the thermal sensors into DC counts usable by the DCS (detector control system), are not designed for these temperatures in which the counts exceed their saturation and therefor had to be replaced. In my project I was in charge of handling the emplacement and calibration of the new PLC cards to the TOB (tracker outer barrel) control system.

  20. Assay for calcium channels

    Energy Technology Data Exchange (ETDEWEB)

    Glossmann, H.; Ferry, D.R.

    1985-01-01

    This chapter focuses on biochemical assays for Ca/sup 2 +/-selective channels in electrically excitable membranes which are blocked in electrophysiological and pharmacological experiments by verapamil, 1,4-dihydropyridines, diltiazen (and various other drugs), as well as inorganic di- or trivalent cations. The strategy employed is to use radiolabeled 1,4-dihydropyridine derivatives which block calcium channels with ED/sub 50/ values in the nanomolar range. Although tritiated d-cis-diltiazem and verapamil can be used to label calcium channels, the 1,4-dihydropyridines offer numerous advantages. The various sections cover tissue specificity of channel labeling, the complex interactions of divalent cations with the (/sup 3/H)nimodipine-labeled calcium channels, and the allosteric regulation of (/sup 3/H)nimodipine binding by the optically pure enantiomers of phenylalkylamine and benzothiazepine calcium channel blockers. A comparison of the properties of different tritiated 1,4-dihydropyridine radioligands and the iodinated channel probe (/sup 125/I)iodipine is given.

  1. THz spectrometer calibration at FELIX

    Energy Technology Data Exchange (ETDEWEB)

    Koevener, Toke; Wunderlich, Steffen; Peier, Peter; Hass, Eugen; Schmidt, Bernhard [Deutsches Elektronen-Synchrotron, Hamburg (Germany)

    2016-07-01

    Coherent radiation spectroscopy is a suitable method for longitudinal electron bunch diagnostics at femtosecond bunch lengths. The absolute value of the longitudinal form factor, that is connected to the longitudinal profile, can be retrieved by measuring the intensity spectrum of a coherent transition radiation source at FLASH. The response function of the used spectrometer has to be well known in absolute values in order to perform accurate measurements. Until now, the response was predicted by calculations. As the free-electron lasers at the FELIX facility in Nijmegen (NL) provide quasi-monochromatic beams that can be tuned in a wide spectral range at micrometer wavelengths, a calibration campaign for two THz spectrometers was performed at this facility with the goal to deduce their response function. Here we present the setup at FELIX that was used for the calibration scans, the achieved scan ranges and the collected data. Furthermore, the analysis of the measured data is discussed. The results are then compared to the previous calculations of the response functions.

  2. Hyperpolarized NMR Probes for Biological Assays

    Directory of Open Access Journals (Sweden)

    Sebastian Meier

    2014-01-01

    Full Text Available During the last decade, the development of nuclear spin polarization enhanced (hyperpolarized molecular probes has opened up new opportunities for studying the inner workings of living cells in real time. The hyperpolarized probes are produced ex situ, introduced into biological systems and detected with high sensitivity and contrast against background signals using high resolution NMR spectroscopy. A variety of natural, derivatized and designed hyperpolarized probes has emerged for diverse biological studies including assays of intracellular reaction progression, pathway kinetics, probe uptake and export, pH, redox state, reactive oxygen species, ion concentrations, drug efficacy or oncogenic signaling. These probes are readily used directly under natural conditions in biofluids and are often directly developed and optimized for cellular assays, thus leaving little doubt about their specificity and utility under biologically relevant conditions. Hyperpolarized molecular probes for biological NMR spectroscopy enable the unbiased detection of complex processes by virtue of the high spectral resolution, structural specificity and quantifiability of NMR signals. Here, we provide a survey of strategies used for the selection, design and use of hyperpolarized NMR probes in biological assays, and describe current limitations and developments.

  3. Simultaneous estimation of diet composition and calibration coefficients with fatty acid signature data

    Science.gov (United States)

    Bromaghin, Jeffrey; Budge, Suzanne M.; Thiemann, Gregory W.; Rode, Karyn D.

    2017-01-01

    Knowledge of animal diets provides essential insights into their life history and ecology, although diet estimation is challenging and remains an active area of research. Quantitative fatty acid signature analysis (QFASA) has become a popular method of estimating diet composition, especially for marine species. A primary assumption of QFASA is that constants called calibration coefficients, which account for the differential metabolism of individual fatty acids, are known. In practice, however, calibration coefficients are not known, but rather have been estimated in feeding trials with captive animals of a limited number of model species. The impossibility of verifying the accuracy of feeding trial derived calibration coefficients to estimate the diets of wild animals is a foundational problem with QFASA that has generated considerable criticism. We present a new model that allows simultaneous estimation of diet composition and calibration coefficients based only on fatty acid signature samples from wild predators and potential prey. Our model performed almost flawlessly in four tests with constructed examples, estimating both diet proportions and calibration coefficients with essentially no error. We also applied the model to data from Chukchi Sea polar bears, obtaining diet estimates that were more diverse than estimates conditioned on feeding trial calibration coefficients. Our model avoids bias in diet estimates caused by conditioning on inaccurate calibration coefficients, invalidates the primary criticism of QFASA, eliminates the need to conduct feeding trials solely for diet estimation, and consequently expands the utility of fatty acid data to investigate aspects of ecology linked to animal diets.

  4. An accurate system for onsite calibration of electronic transformers with digital output

    Science.gov (United States)

    Zhi, Zhang; Li, Hong-Bin

    2012-06-01

    Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differential method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability.

  5. An accurate system for onsite calibration of electronic transformers with digital output

    Energy Technology Data Exchange (ETDEWEB)

    Zhi Zhang; Li Hongbin [CEEE of HuaZhong University of Science and Technology, Wuhan 430074 (China); State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan 430074 (China)

    2012-06-15

    Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differential method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability.

  6. A novel nonradioactive CFDA assay to monitor the cellular immune response in myeloid leukemia.

    Science.gov (United States)

    Yang, Ting; Chen, Zhi-zhe; Kolb, Hans-Jochem; Buhmann, Raymund

    2013-04-01

    Donor lymphocyte transfusion (DLT) may induce the graft-versus-leukemia (GVL) effect for patients with AML relapsed after transplant. However, AML is a highly diverse disease and the limited overall efficacy of DLT in clinical practice emphasizes the importance of identifying a specific subgroup of patients who might benefit from this treatment approach. To monitor the cellular immune response after DLT, we developed an active specific immunization strategy using in vitro generated AML-trained T cells to induce a highly specific antileukemic T-cell response and thus established a novel nonradioactive assay system to assess the antileukemia immunity by flow cytometry, correlated with [3H]-thymidine uptake. The myeloid blasts derived from five patients with AML relapsed post-allogeneic hematopoietic stem cell transplantation (allo-HSCT) were first labeled with CFDA (5,6-carboxyfluorescein diacetate succinimidyl ester). To analyze the growth inhibitory potential of the donor T cells trained by AML progenitor cells, the myeloid blasts were induced to proliferate by means of a cytokine cocktail (50ng/mL of SCF; 25ng/mL of IL-3; 100ng/mL of GM-CSF; 100ng/mL of G-CSF; 2U/mL of EPO; 0.47g/L of transferrin; and 5×10(-5)mmol/L of 2-ME). The T cell mediated growth inhibitory potential was detected after 5 days by flow cytometry and correlated with [3H]-thymidine uptake. The simultaneous use of TO-PRO-dye and calibrate beads allowed not only the cell viability to be known but also allowed quantification of the effector function. Here, we applied a CFDA dye to track the proliferation and expansion of AML blasts in response to the cytokine cocktail in vitro. AML-trained T cells, expressed high levels of the activation markers CD25 and CD69, and were generated to recognize the leukemic progenitor cells and inhibit cytokine-induced leukemic cell proliferation, which is an active specific immunization strategy circumventing the identification of leukemia-associated antigens. The

  7. Design Diversity

    DEFF Research Database (Denmark)

    Dankl, Kathrina

    2014-01-01

    The publication 'Design Diversity', an exhibition catalogue, focuses on aging and design – a product culture in transformation that aims to help change conventional notions of the later years of life. Age is positioned as a generational issue that has the same relevance for all age groups....... The exhibition is oriented along disciplines such as inclusive design, which calls for products to be designed in such a way that they are equally attractive to people of all ages. Despite the existence of innovative design concepts, the number of well-designed products available on the market is low. While many...... design projects not devote themselves to the actual challenges of aging? Do the channels of communication between designers and their target group perhaps not work? The exhibition is organized into four showcases along the themes "Housing," "Networking," "Supporting," and "Moving." Exhibition visitors...

  8. Exposing diversity

    DEFF Research Database (Denmark)

    Nørtoft, Kamilla; Nordentoft, Helle Merete

    . A prominent research theme in health care studies is, therefore, to explicate the gap between theory and practice. The question this paper addresses is how a learning environment can be designed to bridge this theory-practice gap, expose the differences in situated interactions and qualify health...... in the homes of older people and in pedagogical institutions targeting older people. In the paper we look at the potentials and challenges in working with ethnographic video narratives as a pedagogical tool. Our findings indicate that the use of video narratives has the potential to expose the diversity...... focus on their own professional discipline and its tasks 2) stimulates collaborative learning when they discuss their different interpretations of the ethnographic video narratives and achieve a deeper understanding of each other’s work and their clients’ lifeworlds, which might lead to a better...

  9. Diversity Measures

    Directory of Open Access Journals (Sweden)

    MSc. Mentor Ademaj

    2012-06-01

    Full Text Available Diversity measures are a type of non-criminal measures foreseen in the Chapter IV of the Code of Juvenile Justice, which may be imposed on juvenile perpetrators of criminal acts. These measures can be applied in cases of minor offenses, for which is foreseen the criminal sanction with a fine or imprisonment up to three years or for criminal offenses committed by negligence for which is foreseen the sentence up to five years of imprisonment, except those cases that result in death. With the imposition of these measures is intended to prevent criminal proceedings against juveniles whenever is possible, rehabilitation and reintegration of juvenile in his/her community and the prevention of recidivist behaviour. Competent authority to impose them is the public prosecutor, the juvenile judge and juvenile court. And they are executed by the Kosovo Correctional Service.

  10. CALIBRATION OF SEISMIC ATTRIBUTES FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Wayne D. Pennington

    2001-04-01

    The project, ''Calibration of Seismic Attributes for Reservoir Calibration,'' is on schedule and making unplanned discoveries in addition to those intended when the project commenced. The discoveries, planned and unplanned, can be grouped into four classes: pitfalls to avoid in interpretation of seismic attributes; suggested workflows to follow in working with seismic attributes; new methods of calculating certain new attributes which we feel to be useful; and new theoretical approaches to certain petrophysical properties. We are using data from Wyoming, North Texas, South Texas, and the Gulf of Mexico offshore of Louisiana. These environments provide a diverse array of physical conditions and rock types, and a variety of interpretation methods to be applied to them. The Wyoming field is a very difficult one, including alternating layers of thin beds of coals, shales, and hard sandstones, and there may be an observable effect due to hydrocarbon production; we are using this field as the ''test'' of those techniques and methods we have developed or that we prefer based on our work on the other fields. Work on this field is still underway, although progressing nicely. The work on the public domain data sets in Texas, Boonsville and Stratton, is complete except for some minor additional processing steps, and final write-ups are underway. The work on the Gulf of Mexico field has been completed to the extent originally planned, but it has led us to such important new observations and discoveries that we have expanded our original scope to include time-lapse studies and petrophysical aspects of pressure changes; work on this expanded scope is continuing. Presentations have been made at professional-society meetings, company offices, consortium workshops, and university settings. Papers, including one review paper on ''Reservoir Geophysics'' have been published. Several Master's theses, which will spin off

  11. Effects of Serum Creatinine Calibration on Estimated Renal Function in African Americans: the Jackson Heart Study

    Science.gov (United States)

    Wang, Wei; Young, Bessie A.; Fülöp, Tibor; de Boer, Ian H.; Boulware, L. Ebony; Katz, Ronit; Correa, Adolfo; Griswold, Michael E.

    2015-01-01

    Background The calibration to Isotope Dilution Mass Spectroscopy (IDMS) traceable creatinine is essential for valid use of the new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation to estimate the glomerular filtration rate (GFR). Methods For 5,210 participants in the Jackson Heart Study (JHS), serum creatinine was measured with a multipoint enzymatic spectrophotometric assay at the baseline visit (2000–2004) and re-measured using the Roche enzymatic method, traceable to IDMS in a subset of 206 subjects. The 200 eligible samples (6 were excluded, 1 for failure of the re-measurement and 5 for outliers) were divided into three disjoint sets - training, validation, and test - to select a calibration model, estimate true errors, and assess performance of the final calibration equation. The calibration equation was applied to serum creatinine measurements of 5,210 participants to estimate GFR and the prevalence of CKD. Results The selected Deming regression model provided a slope of 0.968 (95% Confidence Interval (CI), 0.904 to 1.053) and intercept of −0.0248 (95% CI, −0.0862 to 0.0366) with R squared 0.9527. Calibrated serum creatinine showed high agreement with actual measurements when applying to the unused test set (concordance correlation coefficient 0.934, 95% CI, 0.894 to 0.960). The baseline prevalence of CKD in the JHS (2000–2004) was 6.30% using calibrated values, compared with 8.29% using non-calibrated serum creatinine with the CKD-EPI equation (P < 0.001). Conclusions A Deming regression model was chosen to optimally calibrate baseline serum creatinine measurements in the JHS and the calibrated values provide a lower CKD prevalence estimate. PMID:25806862

  12. Assessing calibration of prognostic risk scores.

    Science.gov (United States)

    Crowson, Cynthia S; Atkinson, Elizabeth J; Therneau, Terry M

    2016-08-01

    Current methods used to assess calibration are limited, particularly in the assessment of prognostic models. Methods for testing and visualizing calibration (e.g. the Hosmer-Lemeshow test and calibration slope) have been well thought out in the binary regression setting. However, extension of these methods to Cox models is less well known and could be improved. We describe a model-based framework for the assessment of calibration in the binary setting that provides natural extensions to the survival data setting. We show that Poisson regression models can be used to easily assess calibration in prognostic models. In addition, we show that a calibration test suggested for use in survival data has poor performance. Finally, we apply these methods to the problem of external validation of a risk score developed for the general population when assessed in a special patient population (i.e. patients with particular comorbidities, such as rheumatoid arthritis). © The Author(s) 2013.

  13. Calibration of Nacelle-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents the result of the lidar calibration performed for a two-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  14. Calibration of Nacelle-based Lidar instrument

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Courtney, Michael

    This report presents the result of the lidar calibration performed for a four-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark.Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements...... with measurement uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  15. Oxygen-Mass-Flow Calibration Cell

    Science.gov (United States)

    Martin, Robert E.

    1996-01-01

    Proposed calibration standard for mass flow rate of oxygen based on conduction of oxygen ions through solid electrolyte membrane made of zirconia and heated to temperature of 1,000 degrees C. Flow of oxygen ions proportional to applied electric current. Unaffected by variations in temperature and pressure, and requires no measurement of volume. Calibration cell based on concept used to calibrate variety of medical and scientific instruments required to operate with precise rates of flow of oxygen.

  16. Geometrical camera calibration with diffractive optical elements.

    Science.gov (United States)

    Bauer, M; Griessbach, D; Hermerschmidt, A; Krüger, S; Scheele, M; Schischmanow, A

    2008-12-08

    Traditional methods for geometrical camera calibration are based on calibration grids or single pixel illumination by collimated light. A new method for geometrical sensor calibration by means of diffractive optical elements (DOE) in connection with a laser beam equipment is presented. This method can be especially used for 2D-sensor array systems but in principle also for line scanners. (c) 2008 Optical Society of America

  17. Does staff diversity imply openness to diversity?

    DEFF Research Database (Denmark)

    Lauring, Jakob; Selmer, Jan

    2013-01-01

    from diverse university departments to a self-report electronic survey. Findings – It was found that diversity-related internationalization (cultural and linguistic) was generally positively related to favorable diversity attitudes. Inherent demographic diversity (age and gender), on the other hand...... university departments in Denmark. The authors set out to investigate the relationship between different types of staff diversity and openness to diversity in terms of linguistic, visible, value, and informational heterogeneity. Design/methodology/approach – This study uses responses from 489 staff members......, was unrelated or negatively associated with positive diversity attitudes. Originality/value – Few studies deal with the role of staff diversity and no prior studies the authors know of have examined the link between diversity types and openness to diversity....

  18. The long term stability of lidar calibrations

    DEFF Research Database (Denmark)

    Courtney, Michael; Gayle Nygaard, Nicolai

    Wind lidars are now used extensively for wind resource measurements. One of the requirements for the data to be accepted in support of project financing (so-called ‘banka-bility’) is to demonstrate the long-term stability of lidar cali-brations. Calibration results for six Leosphere WindCube li-dars......-ters pertaining in the different calibration periods. This is supported by sliding-window analyses of one lidar at one location where the same order of variation is observed as between pre-service and post-service calibrations....

  19. Calibration services for medical applications of radiation

    Energy Technology Data Exchange (ETDEWEB)

    DeWerd, L.A.

    1993-12-31

    Calibration services for the medical community applications of radiation involve measuring radiation precisely and having traceability to the National Institute of Standards and Technology (NIST). Radiation therapy applications involve the use of ionization chambers and electrometers for external beams and well-type ionization chamber systems as well as radioactive sources for brachytherapy. Diagnostic x-ray applications involve ionization chamber systems and devices to measure other parameters of the x-ray machine, such as non-invasive kVp meters. Calibration laboratories have been established to provide radiation calibration services while maintaining traceability to NIST. New radiation applications of the medical community spur investigation to provide the future calibration needs.

  20. Sloan Digital Sky Survey Photometric Calibration Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Marriner, John; /Fermilab

    2012-06-29

    The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

  1. Uav Cameras: Overview and Geometric Calibration Benchmark

    Science.gov (United States)

    Cramer, M.; Przybilla, H.-J.; Zurhorst, A.

    2017-08-01

    Different UAV platforms and sensors are used in mapping already, many of them equipped with (sometimes) modified cameras as known from the consumer market. Even though these systems normally fulfil their requested mapping accuracy, the question arises, which system performs best? This asks for a benchmark, to check selected UAV based camera systems in well-defined, reproducible environments. Such benchmark is tried within this work here. Nine different cameras used on UAV platforms, representing typical camera classes, are considered. The focus is laid on the geometry here, which is tightly linked to the process of geometrical calibration of the system. In most applications the calibration is performed in-situ, i.e. calibration parameters are obtained as part of the project data itself. This is often motivated because consumer cameras do not keep constant geometry, thus, cannot be seen as metric cameras. Still, some of the commercial systems are quite stable over time, as it was proven from repeated (terrestrial) calibrations runs. Already (pre-)calibrated systems may offer advantages, especially when the block geometry of the project does not allow for a stable and sufficient in-situ calibration. Especially for such scenario close to metric UAV cameras may have advantages. Empirical airborne test flights in a calibration field have shown how block geometry influences the estimated calibration parameters and how consistent the parameters from lab calibration can be reproduced.

  2. Pressure reciprocity calibration of a MEMS microphone.

    Science.gov (United States)

    Wagner, Randall P; Fick, Steven E

    2017-09-01

    This article reports the first use of the pressure reciprocity technique to calibrate a micro-electromechanical system (MEMS) microphone. This standardized primary calibration method is conventionally used to calibrate laboratory standard microphones. Results for the pressure reciprocity calibration of a MEMS microphone and two laboratory standard microphones are presented for the frequency range 100-10 000 Hz. Because the amplifier in the MEMS microphone package prevents reciprocal operation, this microphone was used only as a receiver of sound. A description of the procedure is presented along with checks of the measurement results and data regarding the uncertainties of these results.

  3. Phase A: calibration concepts for HIRES

    Science.gov (United States)

    Huke, Philipp; Origlia, Livia; Riva, Marco; Charsley, Jake; McCracken, Richard; Reid, Derryck; Kowzan, Grzegorz; Maslowski, Piotr; Disseau, Karen; Schäfer, Sebastian; Broeg, Christopher; Sarajlic, Mirsad; Dolon, François; Korhonen, Heidi; Reiners, Ansgar; Boisse, Isabelle; Perruchot, Sandrine; Ottogalli, Sebastien; Pepe, Francesco; Oliva, Ernesto

    2017-06-01

    The instrumentation plan for the E-ELT foresees a High Resolution Spectrograph (HIRES). Among its main goals are the detection of atmospheres of exoplanets and the determination of fundamental physical constants. For this, high radial velocity precision and accuracy are required. HIRES will be designed for maximum intrinsic stability. Systematic errors from effects like intrapixel variations or random errors like fiber noise need to be calibrated. Based on the main requirements for the calibration of HIRES, we discuss different potential calibration sources and how they can be applied. We outline the frequency calibration concept for HIRES using these sources.

  4. FY2008 Calibration Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, Bret D.; Myers, Tanya L.; Broocks, Bryan T.

    2009-01-01

    The Calibrations project has been exploring alternative technologies for calibration of passive sensors in the infrared (IR) spectral region. In particular, we have investigated using quantum cascade lasers (QCLs) because these devices offer several advantages over conventional blackbodies such as reductions in size and weight while providing a spectral source in the IR with high output power. These devices can provide a rapid, multi-level radiance scheme to fit any nonlinear behavior as well as a spectral calibration that includes the fore-optics, which is currently not available for on-board calibration systems.

  5. Luminosity calibration from elastic scattering

    CERN Document Server

    Stenzel, H

    2006-01-01

    The absolute luminosity of the LHC at the ATLAS interaction point will be calibrated by the measurement of the t-distribution of elastic pp-scattering in the Coulomb-Nuclear interference region. The ALFA detector housed in Roman Pots located 240m away from IP1 is designed to approach the beam at mm distance and to measure elastic pp-scattering at micro-radian scattering angles. This measurement will be performed with dedicated runs using a special beam optics with high beta* and parallel-to-point focusing in order to access the Coulomb regime. In this note the expected performance of this method, evaluated with a simulation of the experimental set-up, is presented.

  6. Metrology - Beyond the Calibration Lab

    Science.gov (United States)

    Mimbs, Scott M.

    2008-01-01

    We rely on data from measurements every day; a gas-pump, a speedometer, and a supermarket weight scale are just three examples of measurements we use to make decisions. We generally accept the data from these measurements as "valid." One reason we can accept the data is the "legal metrology" requirements established and regulated by the government in matters of commerce. The measurement data used by NASA, other government agencies, and industry can be critical to decisions which affect everything from economic viability, to mission success, to the security of the nation. Measurement data can even affect life and death decisions. Metrology requirements must adequately provide for risks associated with these decisions. To do this, metrology must be integrated into all aspects of an industry including research, design, testing, and product acceptance. Metrology, the science of measurement, has traditionally focused on the calibration of instruments, and although instrument calibration is vital, it is only a part of the process that assures quality in measurement data. For example, measurements made in research can influence the fundamental premises that establish the design parameters, which then flow down to the manufacturing processes, and eventually impact the final product. Because a breakdown can occur anywhere within this cycle, measurement quality assurance has to be integrated into every part of the life-cycle process starting with the basic research and ending with the final product inspection process. The purpose of this paper is to discuss the role of metrology in the various phases of a product's life-cycle. For simplicity, the cycle will be divided in four broad phases, with discussions centering on metrology within NASA. .

  7. Teaching Diversity

    Directory of Open Access Journals (Sweden)

    Kay Young McChesney

    2015-10-01

    Full Text Available This article is targeted to faculty teaching race and ethnicity, racism, diversity, and multicultural courses. Many students equate race with skin color. The premise of this article is that to teach students about the social construction of race, teachers must first know enough science to teach students that race is not biological. This article examines the biology of race by showing how advances in DNA sequencing led to genetics research that supports arguments that race is not biological. DNA comparisons show that all human populations living today are one species that came from Africa. The article explains the migration of humans out of Africa about 60,000 years ago and how they populated Australia, then Asia, Europe, and the Americas. The article shows how recent research maps the timing of the migration and admixture of specific population groups into Europe and India. The article shows how a mutation in one nucleotide can result in a trait like blue eyes, or Hemoglobin S (which confers resistance to malaria, which can be subject to evolution through natural selection. DNA comparisons show how natural selection shaped the genetics of human skin color to adapt to less UV light in the northern latitudes of Europe and Asia. The article shows that there is no relation between skin color or other “racial” characteristics and complex traits like intelligence. The science in this article will help teachers explain that as race is not biological, race is socially constructed and culturally enacted.

  8. Early penguin fossils, plus mitochondrial genomes, calibrate avian evolution.

    Science.gov (United States)

    Slack, Kerryn E; Jones, Craig M; Ando, Tatsuro; Harrison, G L Abby; Fordyce, R Ewan; Arnason, Ulfur; Penny, David

    2006-06-01

    Testing models of macroevolution, and especially the sufficiency of microevolutionary processes, requires good collaboration between molecular biologists and paleontologists. We report such a test for events around the Late Cretaceous by describing the earliest penguin fossils, analyzing complete mitochondrial genomes from an albatross, a petrel, and a loon, and describe the gradual decline of pterosaurs at the same time modern birds radiate. The penguin fossils comprise four naturally associated skeletons from the New Zealand Waipara Greensand, a Paleocene (early Tertiary) formation just above a well-known Cretaceous/Tertiary boundary site. The fossils, in a new genus (Waimanu), provide a lower estimate of 61-62 Ma for the divergence between penguins and other birds and thus establish a reliable calibration point for avian evolution. Combining fossil calibration points, DNA sequences, maximum likelihood, and Bayesian analysis, the penguin calibrations imply a radiation of modern (crown group) birds in the Late Cretaceous. This includes a conservative estimate that modern sea and shorebird lineages diverged at least by the Late Cretaceous about 74 +/- 3 Ma (Campanian). It is clear that modern birds from at least the latest Cretaceous lived at the same time as archaic birds including Hesperornis, Ichthyornis, and the diverse Enantiornithiformes. Pterosaurs, which also coexisted with early crown birds, show notable changes through the Late Cretaceous. There was a decrease in taxonomic diversity, and small- to medium-sized species disappeared well before the end of the Cretaceous. A simple reading of the fossil record might suggest competitive interactions with birds, but much more needs to be understood about pterosaur life histories. Additional fossils and molecular data are still required to help understand the role of biotic interactions in the evolution of Late Cretaceous birds and thus to test that the mechanisms of microevolution are sufficient to explain

  9. Sulforhodamine B assay and chemosensitivity.

    Science.gov (United States)

    Voigt, Wieland

    2005-01-01

    The sulforhodamine B (SRB) assay was developed by Skehan and colleagues to measure drug-induced cytotoxicity and cell proliferation for large-scale drug-screening applications. Its principle is based on the ability of the protein dye sulforhodamine B to bind electrostatically and pH dependent on protein basic amino acid residues of trichloroacetic acid-fixed cells. Under mild acidic conditions it binds to and under mild basic conditions it can be extracted from cells and solubilized for measurement. Results of the SRB assay were linear with cell number and cellular protein measured at cellular densities ranging from 1 to 200% of confluence. Its sensitivity is comparable with that of several fluorescence assays and superior to that of Lowry or Bradford. The signal-to-noise ratio is favorable and the resolution is 1000-2000 cells/well. It performed similarly compared to other cytotoxicity assays such as MTT or clonogenic assay. The SRB assay possesses a colorimetric end point and is nondestructive and indefinitely stable. These practical advances make the SRB assay an appropriate and sensitive assay to measure drug-induced cytotoxicity even at large-scale application.

  10. Digital Assays Part II: Digital Protein and Cell Assays.

    Science.gov (United States)

    Basu, Amar S

    2017-08-01

    A digital assay is one in which the sample is partitioned into many containers such that each partition contains a discrete number of biological entities (0, 1, 2, 3, . . .). A powerful technique in the biologist's toolkit, digital assays bring a new level of precision in quantifying nucleic acids, measuring proteins and their enzymatic activity, and probing single-cell genotype and phenotype. Where part I of this review focused on the fundamentals of partitioning and digital PCR, part II turns its attention to digital protein and cell assays. Digital enzyme assays measure the kinetics of single proteins with enzymatic activity. Digital enzyme-linked immunoassays (ELISAs) quantify antigenic proteins with 2 to 3 log lower detection limit than conventional ELISA, making them well suited for low-abundance biomarkers. Digital cell assays probe single-cell genotype and phenotype, including gene expression, intracellular and surface proteins, metabolic activity, cytotoxicity, and transcriptomes (scRNA-seq). These methods exploit partitioning to 1) isolate single cells or proteins, 2) detect their activity via enzymatic amplification, and 3) tag them individually by coencapsulating them with molecular barcodes. When scaled, digital assays reveal stochastic differences between proteins or cells within a population, a key to understanding biological heterogeneity. This review is intended to give a broad perspective to scientists interested in adopting digital assays into their workflows.

  11. Disagreement between Human Papillomavirus Assays

    DEFF Research Database (Denmark)

    Rebolj, Matejka; Preisler, Sarah; Ejegod, Ditte Møller

    2014-01-01

    We aimed to determine the disagreement in primary cervical screening between four human papillomavirus assays: Hybrid Capture 2, cobas, CLART, and APTIMA. Material from 5,064 SurePath samples of women participating in routine cervical screening in Copenhagen, Denmark, was tested with the four...... of considerable disagreement between human papillomavirus assays. This suggested that the extent of disagreement in primary screening is neither population- nor storage media-specific, leaving assay design differences as the most probable cause. The substantially different selection of women testing positive...... on the various human papillomavirus assays represents an unexpected challenge for the choice of an assay in primary cervical screening, and for follow up of in particular HPV positive/cytology normal women....

  12. SELECTION AND TREATMENT OF DATA FOR RADIOCARBON CALIBRATION : AN UPDATE TO THE INTERNATIONAL CALIBRATION (INTCAL) CRITERIA

    NARCIS (Netherlands)

    Reimer, Paula J.; Bard, Edouard; Bayliss, Alex; Beck, J. Warren; Blackwell, Paul G.; Ramsey, Christopher Bronk; Brown, David M.; Buck, Caitlin E.; Edwards, R. Lawrence; Friedrich, Michael; Grootes, Pieter M.; Guilderson, Thomas P.; Haflidason, Haflidi; Hajdas, Irka; Hatte, Christine; Heaton, Timothy J.; Hogg, Alan G.; Hughen, Konrad A.; Kaiser, K. Felix; Kromer, Bernd; Manning, Sturt W.; Reimer, Ron W.; Richards, David A.; Scott, E. Marian; Southon, John R.; Turney, Christian S. M.; van der Plicht, Johannes

    2013-01-01

    High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind C-14 dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are

  13. Calibration of the ATLAS electromagnetic calorimeter using calibration hits

    CERN Document Server

    Banfi, D; Mandelli, L

    2007-01-01

    In the present note a method to determine the electron energy from the energies measured in an electron cluster is discussed. The method is based on a detailed Monte-Carlo simulation (labeled \\textit{Calibration Hits}) of electrons in the ATLAS detector in which also the energies deposited in the passive and dead materials are recorded. It allows also to compute the different contributions (energy deposited in front, in and behind the Accordion) to the total electron energy. To better understand the various contributions to the energy reconstruction three rounds of simulations have been performed: electrons hitting the middle cell centre, electrons spread uniformly over a cell in absence of magnetic field and electrons spread uniformly over a cell in presence of magnetic field. The method is applied to the Barrel calorimeter and to electrons. Its extension to the End Caps and to photons does not pose problems. In the operative ATLAS conditions an energy resolution sampling term varying from 9.9$\\%$ at $\\eta$=...

  14. Lidar to lidar calibration phase 2

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents the results from phase 2 of a lidar to lidar (L2L) calibration procedure. Phase two of the project included two measurement campaigns conducted at given sites. The purpose was to find out if the lidar-to-lidar calibration procedure can be conducted with similar results...

  15. 40 CFR 89.307 - Dynamometer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Dynamometer calibration. 89.307 Section 89.307 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... dynamometer manufacturer's specifications. (2) Determine the dynamometer calibration moment arm (a distance...

  16. Error-in-variables models in calibration

    Science.gov (United States)

    Lira, I.; Grientschnig, D.

    2017-12-01

    In many calibration operations, the stimuli applied to the measuring system or instrument under test are derived from measurement standards whose values may be considered to be perfectly known. In that case, it is assumed that calibration uncertainty arises solely from inexact measurement of the responses, from imperfect control of the calibration process and from the possible inaccuracy of the calibration model. However, the premise that the stimuli are completely known is never strictly fulfilled and in some instances it may be grossly inadequate. Then, error-in-variables (EIV) regression models have to be employed. In metrology, these models have been approached mostly from the frequentist perspective. In contrast, not much guidance is available on their Bayesian analysis. In this paper, we first present a brief summary of the conventional statistical techniques that have been developed to deal with EIV models in calibration. We then proceed to discuss the alternative Bayesian framework under some simplifying assumptions. Through a detailed example about the calibration of an instrument for measuring flow rates, we provide advice on how the user of the calibration function should employ the latter framework for inferring the stimulus acting on the calibrated device when, in use, a certain response is measured.

  17. Planck 2013 results. V. LFI calibration

    DEFF Research Database (Denmark)

    Planck Collaboration,; Aghanim, N.; Armitage-Caplan, C.

    2014-01-01

    We discuss the methods employed to photometrically calibrate the data acquired by the Low Frequency Instrument on Planck. Our calibration is based on the Solar Dipole, caused by motion of the Solar System with respect to the CMB rest frame, which provides a signal of a few mK with the same spectr...

  18. 21 CFR 862.1150 - Calibrator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calibrator. 862.1150 Section 862.1150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1150 Calibrator...

  19. Self-calibration and biconvex compressive sensing

    Science.gov (United States)

    Ling, Shuyang; Strohmer, Thomas

    2015-11-01

    The design of high-precision sensing devises becomes ever more difficult and expensive. At the same time, the need for precise calibration of these devices (ranging from tiny sensors to space telescopes) manifests itself as a major roadblock in many scientific and technological endeavors. To achieve optimal performance of advanced high-performance sensors one must carefully calibrate them, which is often difficult or even impossible to do in practice. In this work we bring together three seemingly unrelated concepts, namely self-calibration, compressive sensing, and biconvex optimization. The idea behind self-calibration is to equip a hardware device with a smart algorithm that can compensate automatically for the lack of calibration. We show how several self-calibration problems can be treated efficiently within the framework of biconvex compressive sensing via a new method called SparseLift. More specifically, we consider a linear system of equations {\\boldsymbol{y}}={\\boldsymbol{D}}{\\boldsymbol{A}}{\\boldsymbol{x}}, where both {\\boldsymbol{x}} and the diagonal matrix {\\boldsymbol{D}} (which models the calibration error) are unknown. By ‘lifting’ this biconvex inverse problem we arrive at a convex optimization problem. By exploiting sparsity in the signal model, we derive explicit theoretical guarantees under which both {\\boldsymbol{x}} and {\\boldsymbol{D}} can be recovered exactly, robustly, and numerically efficiently via linear programming. Applications in array calibration and wireless communications are discussed and numerical simulations are presented, confirming and complementing our theoretical analysis.

  20. Calibration procedure for fire resistance furnaces

    NARCIS (Netherlands)

    Twilt, L.; Leur, P.H.E. van de; Wickström, U.

    1996-01-01

    On behalf of CEN/TC 127 "Fire Safety in Buildings", a series of tests has been carried out to evaluate and complete the draft calibration procedure for fire resistance furnaces [4]. Fourteen laboratories in nine European countries participated in the test series, each carrying out one calibration

  1. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement unce...

  2. Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement unce...

  3. Optical Tweezer Assembly and Calibration

    Science.gov (United States)

    Collins, Timothy M.

    2004-01-01

    An Optical Tweezer, as the name implies, is a useful tool for precision manipulation of micro and nano scale objects. Using the principle of electromagnetic radiation pressure, an optical tweezer employs a tightly focused laser beam to trap and position objects of various shapes and sizes. These devices can trap micrometer and nanometer sized objects. An exciting possibility for optical tweezers is its future potential to manipulate and assemble micro and nano sized sensors. A typical optical tweezer makes use of the following components: laser, mirrors, lenses, a high quality microscope, stage, Charge Coupled Device (CCD) camera, TV monitor and Position Sensitive Detectors (PSDs). The laser wavelength employed is typically in the visible or infrared spectrum. The laser beam is directed via mirrors and lenses into the microscope. It is then tightly focused by a high magnification, high numerical aperture microscope objective into the sample slide, which is mounted on a translating stage. The sample slide contains a sealed, small volume of fluid that the objects are suspended in. The most common objects trapped by optical tweezers are dielectric spheres. When trapped, a sphere will literally snap into and center itself in the laser beam. The PSD s are mounted in such a way to receive the backscatter after the beam has passed through the trap. PSD s used with the Differential Interference Contrast (DIC) technique provide highly precise data. Most optical tweezers employ lasers with power levels ranging from 10 to 100 miliwatts. Typical forces exerted on trapped objects are in the pico-newton range. When PSDs are employed, object movement can be resolved on a nanometer scale in a time range of milliseconds. Such accuracy, however, can only by utilized by calibrating the optical tweezer. Fortunately, an optical tweezer can be modeled accurately as a simple spring. This allows Hook s Law to be used. My goal this summer at NASA Glenn Research Center is the assembly and

  4. Electromagnetic Calorimeter Calibration with $\\pi^{0}$

    CERN Multimedia

    Puig Navarro, A

    2009-01-01

    Several methods can be used in order to achieve precise calibration of the LHCb Electromagnetic Calorimeter (ECAL) once reasonable cell equalization has been reached. At low transverse energy, the standard calibration procedure is an iterative method based on the fit of the $\\gamma\\gamma$ invariant mass distribution for each cell of the decay $\\pi^{0}\\to\\gamma\\gamma$ with resolved photons. A new technique for generating the combinatorial background of such decays directly from data has been developed. Knowledge of the background could allow an alternative calibration method based on a event by event fit of the same $\\gamma\\gamma$ invariant mass distribution where contributions from groups of cells are considered in a single fit. The background generation procedure and this possible new calibration method are presented in this poster, in addition to an overview of the LHCb Calorimetry system and ECAL calibration techniques.

  5. CERN Radiation Protection (RP) calibration facilities

    CERN Document Server

    AUTHOR|(CDS)2082069; Macián-Juan, Rafael

    Radiation protection calibration facilities are essential to ensure the correct operation of radiation protection instrumentation. Calibrations are performed in specific radiation fields according to the type of instrument to be calibrated: neutrons, photons, X-rays, beta and alpha particles. Some of the instruments are also tested in mixed radiation fields as often encountered close to high-energy particle accelerators. Moreover, calibration facilities are of great importance to evaluate the performance of prototype detectors; testing and measuring the response of a prototype detector to well-known and -characterized radiation fields contributes to improving and optimizing its design and capabilities. The CERN Radiation Protection group is in charge of performing the regular calibrations of all CERN radiation protection devices; these include operational and passive dosimeters, neutron and photon survey-meters, and fixed radiation detectors to monitor the ambient dose equivalent, H*(10), inside CERN accelera...

  6. The ATLAS Electromagnetic Calorimeter Calibration Workshop

    CERN Multimedia

    Hong Ma; Isabelle Wingerter

    The ATLAS Electromagnetic Calorimeter Calibration Workshop took place at LAPP-Annecy from the 1st to the 3rd of October; 45 people attended the workshop. A detailed program was setup before the workshop. The agenda was organised around very focused presentations where questions were raised to allow arguments to be exchanged and answers to be proposed. The main topics were: Electronics calibration Handling of problematic channels Cluster level corrections for electrons and photons Absolute energy scale Streams for calibration samples Calibration constants processing Learning from commissioning Forty-five people attended the workshop. The workshop was on the whole lively and fruitful. Based on years of experience with test beam analysis and Monte Carlo simulation, and the recent operation of the detector in the commissioning, the methods to calibrate the electromagnetic calorimeter are well known. Some of the procedures are being exercised in the commisssioning, which have demonstrated the c...

  7. Calibration biases in logical reasoning tasks

    Directory of Open Access Journals (Sweden)

    Guillermo Macbeth

    2013-08-01

    Full Text Available The aim of this contribution is to present an experimental study about calibration in deductive reasoning tasks. Calibration is defi ned as the empirical convergence or divergence between the objective and the subjective success. The underconfi dence bias is understood as the dominance of the former over the latter. The hypothesis of this study states that the form of the propositions presented in the experiment is critical for calibration phenomena. Affi rmative and negative propositions are distinguished in their cognitive processing. Results suggests that monotonous compound propositions are prone to underconfi dence. An heuristic approach to this phenomenon is proposed. The activation of a monotony heuristic would produce an illusion of simplicity that generates the calibration bias. These evidence is analysed in the context of the metacognitive modeling of calibration phenomena.

  8. Geometric calibration of ERS satellite SAR images

    DEFF Research Database (Denmark)

    Mohr, Johan Jacob; Madsen, Søren Nørvang

    2001-01-01

    Geometric calibration of the European Remote Sensing (ERS) Satellite synthetic aperture radar (SAR) slant range images is important in relation to mapping areas without ground reference points and also in relation to automated processing. The relevant SAR system parameters are discussed and calib......Geometric calibration of the European Remote Sensing (ERS) Satellite synthetic aperture radar (SAR) slant range images is important in relation to mapping areas without ground reference points and also in relation to automated processing. The relevant SAR system parameters are discussed...... on a seven-year ERS-1 and a four-year ERS-2 time series, the long term stability is found to be sufficient to allow a single calibration covering the entire mission period. A descending and an ascending orbit tandem pair of the ESA calibration site on Flevoland, suitable for calibration of ERS SAR processors...

  9. Calibration of an Inertial Measurement Unit

    Science.gov (United States)

    Avrutov, V. V.; Sapegin, A. N.; Stefanishin, Z. S.; Tsisarzh, V. V.

    2017-03-01

    A new method for the calibration of inertial measurement units of strapdown inertial technology is proposed. Such a unit consists of accelerometers, gyroscopes, and a signal processing system. The method of test turns and rotations on a rotary table is used to calibrate the inertial measurement unit. The new method involves measurement of the full angle of turn or final rotation. In fact, it is proposed to turn the inertial measurement unit around the axis of final rotation. To solve the calibration equation, it is necessary to make the rank of the matrix of the calibration equation equal to its order. The results of modeling data demonstrate the efficiency of the new calibration method

  10. Systems and methods of eye tracking calibration

    DEFF Research Database (Denmark)

    2014-01-01

    Methods and systems to facilitate eye tracking control calibration are provided. One or more objects are displayed on a display of a device, where the one or more objects are associated with a function unrelated to a calculation of one or more calibration parameters. The one or more calibration...... parameters relate to a calibration of a calculation of gaze information of a user of the device, where the gaze information indicates where the user is looking. While the one or more objects are displayed, eye movement information associated with the user is determined, which indicates eye movement of one...... or more eye features associated with at least one eye of the user. The eye movement information is associated with a first object location of the one or more objects. The one or more calibration parameters are calculated based on the first object location being associated with the eye movement information....

  11. Optimization of geometrical calibration in pinhole SPECT.

    Science.gov (United States)

    Bequé, Dirk; Nuyts, Johan; Suetens, Paul; Bormans, Guy

    2005-02-01

    Previously, we developed a method to determine the acquisition geometry of a pinhole camera. This information is needed for the correct reconstruction of pinhole single photon emission computed tomography images. The method uses a calibration phantom consisting of three point sources and their positions in the field of view (FOV) influence the accuracy of the geometry estimate. This paper proposes two particular configurations of point sources with specific positions and orientations in the FOV for optimal image reconstruction accuracy. For the proposed calibration setups, inaccuracies of the geometry estimate due to noise in the calibration data, only cause subresolution inaccuracies in reconstructed images. The calibration method also uses a model of the point source configuration, which is only known with limited accuracy. The study demonstrates, however, that, with the proposed calibration setups, the error in reconstructed images is comparable to the error in the phantom model.

  12. Automated calibration of TECAN genesis liquid handling workstation utilizing an online balance and density meter.

    Science.gov (United States)

    Xie, Iris H; Wang, Michael H; Carpenter, Richard; Wu, Henry Y

    2004-02-01

    With robotics widely used in bioanalytical assays, accurate system performance is essential to ensure the quality and productivity of the robotics. In our lab, an automated calibration procedure has been developed to evaluate the precision and accuracy of the TECAN (Research Triangle Park, NC, U.S.A.) Genesis liquid handling system in a bioanalytical laboratory setting. The calibrations were performed by transferring and weighing the solvents automatically on a microbalance controlled by a Gemini program. From the data acquired, calibration reports were generated using a template. The novel aspect of this approach is the use of an on-line balance and a density meter, both of which combine to make the calibration process simple, efficient, and precise. For quantitative bioanalysis, a variety of solvents, including methanol, water, mixed solvents, and plasma, are typically used to prepare standards and unknown samples. Density information is usually unknown for the mixed solvents, and the density of plasma can vary from species to species. However, with the use of a universal density meter, the density could be obtained in seconds. The issue of solvent evaporation during the calibration process was also addressed. Calibration curves were set up for various liquid classes. Pipetting volumes ranged from 10 microL to 900 microL. Precision and accuracy results obtained from the semiannual performance evaluations showed this procedure to be reliable and user-friendly. Using the automated calibration procedure, the calibration and performance evaluation of the robotic system is considerably more efficient, and the incidence of unacceptable precision and accuracy is greatly reduced.

  13. COMPARISON OF METHODS FOR GEOMETRIC CAMERA CALIBRATION

    Directory of Open Access Journals (Sweden)

    J. Hieronymus

    2012-09-01

    Full Text Available Methods for geometric calibration of cameras in close-range photogrammetry are established and well investigated. The most common one is based on test-fields with well-known pattern, which are observed from different directions. The parameters of a distortion model are calculated using bundle-block-adjustment-algorithms. This methods works well for short focal lengths, but is essentially more problematic to use with large focal lengths. Those would require very large test-fields and surrounding space. To overcome this problem, there is another common method for calibration used in remote sensing. It employs measurements using collimator and a goniometer. A third calibration method uses diffractive optical elements (DOE to project holograms of well known pattern. In this paper these three calibration methods are compared empirically, especially in terms of accuracy. A camera has been calibrated with those methods mentioned above. All methods provide a set of distortion correction parameters as used by the photogrammetric software Australis. The resulting parameter values are very similar for all investigated methods. The three sets of distortion parameters are crosscompared against all three calibration methods. This is achieved by inserting the gained distortion parameters as fixed input into the calibration algorithms and only adjusting the exterior orientation. The RMS (root mean square of the remaining image coordinate residuals are taken as a measure of distortion correction quality. There are differences resulting from the different calibration methods. Nevertheless the measure is small for every comparison, which means that all three calibration methods can be used for accurate geometric calibration.

  14. Fabrication and Calibration of FORTIS

    Science.gov (United States)

    Fleming, Brian T.; McCandliss, Stephan R.; Kaiser, Mary Elizabeth; Kruk, Jeffery; Feldman, Paul D.; Kutyrev, Alexander S.; Li, Mary J.; Rapchun, David A.; Lyness, Eric; Moseley, S. H.; hide

    2011-01-01

    The Johns Hopkins University sounding rocket group is entering the final fabrication phase of the Far-ultraviolet Off Rowland-circle Telescope for Imaging and Spectroscopy (FORTIS); a sounding rocket borne multi-object spectro-telescope designed to provide spectral coverage of 43 separate targets in the 900 - 1800 Angstrom bandpass over a 30' x 30' field-of-view. Using "on-the-fly" target acquisition and spectral multiplexing enabled by a GSFC microshutter array, FORTIS will be capable of observing the brightest regions in the far-UV of nearby low redshift (z approximately 0.002 - 0.02) star forming galaxies to search for Lyman alpha escape, and to measure the local gas-to-dust ratio. A large area (approximately 45 mm x 170 mm) microchannel plate detector built by Sensor Sciences provides an imaging channel for targeting flanked by two redundant spectral outrigger channels. The grating is ruled directly onto the secondary mirror to increase efficiency. In this paper, we discuss the recent progress made in the development and fabrication of FORTIS, as well as the results of early calibration and characterization of our hardware, including mirror/grating measurements, detector performance, and early operational tests of the micro shutter arrays.

  15. Developing Spent Fuel Assembly for Advanced NDA Instrument Calibration - NGSI Spent Fuel Project

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jianwei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gauld, Ian C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Banfield, James [GE Hitachi Nuclear Energy, Wilmington, NC (United States); Skutnik, Steven [Univ. of Tennessee, Knoxville, TN (United States)

    2014-02-01

    This report summarizes the work by Oak Ridge National Laboratory to investigate the application of modeling and simulation to support the performance assessment and calibration of the advanced nondestructive assay (NDA) instruments developed under the Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) Project. Advanced NDA instrument calibration will likely require reference spent fuel assemblies with well-characterized nuclide compositions that can serve as working standards. Because no reference spent fuel standard currently exists, and the practical ability to obtain direct measurement of nuclide compositions using destructive assay (DA) measurements of an entire fuel assembly is prohibitive in the near term due to the complexity and cost of spent fuel experiments, modeling and simulation will be required to construct such reference fuel assemblies. These calculations will be used to support instrument field tests at the Swedish Interim Storage Facility (Clab) for Spent Nuclear Fuel.

  16. Intercomparison and calibration of dose calibrators used in nuclear medicine facilities

    CERN Document Server

    Costa, A M D

    2003-01-01

    The aim of this work was to establish a working standard for intercomparison and calibration of dose calibrators used in most of nuclear medicine facilities for the determination of the activity of radionuclides administered to patients in specific examinations or therapeutic procedures. A commercial dose calibrator, a set of standard radioactive sources, and syringes, vials and ampoules with radionuclide solutions used in nuclear medicine were utilized in this work. The commercial dose calibrator was calibrated for radionuclide solutions used in nuclear medicine. Simple instrument tests, such as linearity response and variation response with the source volume at a constant source activity concentration were performed. This instrument may be used as a reference system for intercomparison and calibration of other activity meters, as a method of quality control of dose calibrators utilized in nuclear medicine facilities.

  17. Blind calibration of radio interferometric arrays using sparsity constraints and its implications for self-calibration

    Science.gov (United States)

    Chiarucci, Simone; Wijnholds, Stefan J.

    2018-02-01

    Blind calibration, i.e. calibration without a priori knowledge of the source model, is robust to the presence of unknown sources such as transient phenomena or (low-power) broad-band radio frequency interference that escaped detection. In this paper, we present a novel method for blind calibration of a radio interferometric array assuming that the observed field only contains a small number of discrete point sources. We show the huge computational advantage over previous blind calibration methods and we assess its statistical efficiency and robustness to noise and the quality of the initial estimate. We demonstrate the method on actual data from a Low-Frequency Array low-band antenna station showing that our blind calibration is able to recover the same gain solutions as the regular calibration approach, as expected from theory and simulations. We also discuss the implications of our findings for the robustness of regular self-calibration to poor starting models.

  18. Biological assays in microfabricated structures

    Science.gov (United States)

    Fishman, Daniel M.; Fare, Thomas L.; Dong, Qianping; Fan, Z. Hugh; Davis, Timothy J.; Kumar, Rajan

    1999-04-01

    Microfluidic control in microfabricated glass channels enables miniaturized, fast, and multianalyte assays. We are applying this technology in several areas, including real- time environmental monitoring for airborne biological agents. Two complementary approaches are being used in parallel. the first is assaying for the presence of nucleotide sequences that are markers for specific hazardous, engineered bacteria. The second is an assay that monitors the functionality of an in vitro biochemical pathway, in which the pathway that is chosen is sensitive to the presence of the class of toxins to be detected. The first approach is discussed here. The detected signal from the nucleic-acid-based assay is from fluorescently labeled probes that hybridize to bead-bound amplified DNA sequences. Detection approaches and their benefits will be discussed.

  19. Microtiter dish biofilm formation assay.

    Science.gov (United States)

    O'Toole, George A

    2011-01-30

    Biofilms are communities of microbes attached to surfaces, which can be found in medical, industrial and natural settings. In fact, life in a biofilm probably represents the predominate mode of growth for microbes in most environments. Mature biofilms have a few distinct characteristics. Biofilm microbes are typically surrounded by an extracellular matrix that provides structure and protection to the community. Microbes growing in a biofilm also have a characteristic architecture generally comprised of macrocolonies (containing thousands of cells) surrounded by fluid-filled channels. Biofilm-grown microbes are also notorious for their resistance to a range of antimicrobial agents including clinically relevant antibiotics. The microtiter dish assay is an important tool for the study of the early stages in biofilm formation, and has been applied primarily for the study of bacterial biofilms, although this assay has also been used to study fungal biofilm formation. Because this assay uses static, batch-growth conditions, it does not allow for the formation of the mature biofilms typically associated with flow cell systems. However, the assay has been effective at identifying many factors required for initiation of biofilm formation (i.e, flagella, pili, adhesins, enzymes involved in cyclic-di-GMP binding and metabolism) and well as genes involved in extracellular polysaccharide production. Furthermore, published work indicates that biofilms grown in microtiter dishes do develop some properties of mature biofilms, such a antibiotic tolerance and resistance to immune system effectors. This simple microtiter dish assay allows for the formation of a biofilm on the wall and/or bottom of a microtiter dish. The high throughput nature of the assay makes it useful for genetic screens, as well as testing biofilm formation by multiple strains under various growth conditions. Variants of this assay have been used to assess early biofilm formation for a wide variety of microbes

  20. Calibration and seasonal adjustment for matched case-control studies of vitamin D and cancer.

    Science.gov (United States)

    Gail, Mitchell H; Wu, Jincao; Wang, Molin; Yaun, Shiaw-Shyuan; Cook, Nancy R; Eliassen, A Heather; McCullough, Marjorie L; Yu, Kai; Zeleniuch-Jacquotte, Anne; Smith-Warner, Stephanie A; Ziegler, Regina G; Carroll, Raymond J

    2016-06-15

    Vitamin D measurements are influenced by seasonal variation and specific assay used. Motivated by multicenter studies of associations of vitamin D with cancer, we formulated an analytic framework for matched case-control data that accounts for seasonal variation and calibrates to a reference assay. Calibration data were obtained from controls sampled within decile strata of the uncalibrated vitamin D values. Seasonal sine-cosine series were fit to control data. Practical findings included the following: (1) failure to adjust for season and calibrate increased variance, bias, and mean square error and (2) analysis of continuous vitamin D requires a variance adjustment for variation in the calibration estimate. An advantage of the continuous linear risk model is that results are independent of the reference date for seasonal adjustment. (3) For categorical risk models, procedures based on categorizing the seasonally adjusted and calibrated vitamin D have near nominal operating characteristics; estimates of log odds ratios are not robust to choice of seasonal reference date, however. Thus, public health recommendations based on categories of vitamin D should also define the time of year to which they refer. This work supports the use of simple methods for calibration and seasonal adjustment and is informing analytic approaches for the multicenter Vitamin D Pooling Project for Breast and Colorectal Cancer. Published 2016. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Published 2016. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  1. Calibrating page sized Gafchromic EBT3 films

    Energy Technology Data Exchange (ETDEWEB)

    Crijns, W.; Maes, F.; Heide, U. A. van der; Van den Heuvel, F. [Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); Department ESAT/PSI-Medical Image Computing, Medical Imaging Research Center, KU Leuven, Herestraat 49, 3000 Leuven (Belgium); Department of Radiation Oncology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium)

    2013-01-15

    Purpose: The purpose is the development of a novel calibration method for dosimetry with Gafchromic EBT3 films. The method should be applicable for pretreatment verification of volumetric modulated arc, and intensity modulated radiotherapy. Because the exposed area on film can be large for such treatments, lateral scan errors must be taken into account. The correction for the lateral scan effect is obtained from the calibration data itself. Methods: In this work, the film measurements were modeled using their relative scan values (Transmittance, T). Inside the transmittance domain a linear combination and a parabolic lateral scan correction described the observed transmittance values. The linear combination model, combined a monomer transmittance state (T{sub 0}) and a polymer transmittance state (T{sub {infinity}}) of the film. The dose domain was associated with the observed effects in the transmittance domain through a rational calibration function. On the calibration film only simple static fields were applied and page sized films were used for calibration and measurements (treatment verification). Four different calibration setups were considered and compared with respect to dose estimation accuracy. The first (I) used a calibration table from 32 regions of interest (ROIs) spread on 4 calibration films, the second (II) used 16 ROIs spread on 2 calibration films, the third (III), and fourth (IV) used 8 ROIs spread on a single calibration film. The calibration tables of the setups I, II, and IV contained eight dose levels delivered to different positions on the films, while for setup III only four dose levels were applied. Validation was performed by irradiating film strips with known doses at two different time points over the course of a week. Accuracy of the dose response and the lateral effect correction was estimated using the dose difference and the root mean squared error (RMSE), respectively. Results: A calibration based on two films was the optimal

  2. Vicarious Calibration of Beijing-1 Multispectral Imagers

    Directory of Open Access Journals (Sweden)

    Zhengchao Chen

    2014-02-01

    Full Text Available For on-orbit calibration of the Beijing-1 multispectral imagers (Beijing-1/MS, a field calibration campaign was performed at the Dunhuang calibration site during September and October of 2008. Based on the in situ data and images from Beijing-1 and Terra/Moderate Resolution Imaging Spectroradiometer (MODIS, three vicarious calibration methods (i.e., reflectance-based, irradiance-based, and cross-calibration were used to calculate the top-of-atmosphere (TOA radiance of Beijing-1. An analysis was then performed to determine or identify systematic and accidental errors, and the overall uncertainty was assessed for each individual method. The findings show that the reflectance-based method has an uncertainty of more than 10% if the aerosol optical depth (AOD exceeds 0.2. The cross-calibration method is able to reach an error level within 7% if the images are selected carefully. The final calibration coefficients were derived from the irradiance-based data for 6 September 2008, with an uncertainty estimated to be less than 5%.

  3. Increased Automation in Stereo Camera Calibration Techniques

    Directory of Open Access Journals (Sweden)

    Brandi House

    2006-08-01

    Full Text Available Robotic vision has become a very popular field in recent years due to the numerous promising applications it may enhance. However, errors within the cameras and in their perception of their environment can cause applications in robotics to fail. To help correct these internal and external imperfections, stereo camera calibrations are performed. There are currently many accurate methods of camera calibration available; however, most or all of them are time consuming and labor intensive. This research seeks to automate the most labor intensive aspects of a popular calibration technique developed by Jean-Yves Bouguet. His process requires manual selection of the extreme corners of a checkerboard pattern. The modified process uses embedded LEDs in the checkerboard pattern to act as active fiducials. Images are captured of the checkerboard with the LEDs on and off in rapid succession. The difference of the two images automatically highlights the location of the four extreme corners, and these corner locations take the place of the manual selections. With this modification to the calibration routine, upwards of eighty mouse clicks are eliminated per stereo calibration. Preliminary test results indicate that accuracy is not substantially affected by the modified procedure. Improved automation to camera calibration procedures may finally penetrate the barriers to the use of calibration in practice.

  4. Calibration of the ROSAT HRI Spectral Response

    Science.gov (United States)

    Prestwich, Andrea H.; Silverman, John; McDowell, Jonathan; Callanan, Paul; Snowden, Steve

    2000-01-01

    The ROSAT High Resolution Imager has a limited (2-band) spectral response. This spectral capability can give X-ray hardness ratios on spatial scales of 5 arcseconds. The spectral response of the center of the detector was calibrated before the launch of ROSAT, but the gain decreases with time and also is a function of position on the detector. To complicate matters further, the satellite is 'wobbled', possibly moving a source across several spatial gain states. These difficulties have prevented the spectral response of the ROSAT High Resolution Imager (HRI) from being used for scientific measurements. We have used Bright Earth data and in-flight calibration sources to map the spatial and temporal gain changes, and written software which will allow ROSAT users to generate a calibrated XSPEC (an x ray spectral fitting package) response matrix and hence determine a calibrated hardness ratio. In this report, we describe the calibration procedure and show how to obtain a response matrix. In Section 2 we give an overview of the calibration procedure, in Section 3 we give a summary of HRI spatial and temporal gain variations. Section 4 describes the routines used to determine the gain distribution of a source. In Sections 5 and 6, we describe in detail how, the Bright Earth database and calibration sources are used to derive a corrected response matrix for a given observation. Finally, Section 7 describes how to use the software.

  5. Calibrators and control samples for bilirubinometers.

    Science.gov (United States)

    Blijenberg, B G; Brügmann, G; Geilenkeuser, W J; Kusyschyn, R; Röhle, G; Schlebusch, H; Schneider, C

    1993-06-01

    The different matrix properties of neonatal serum and commercial control samples can lead to considerable errors in the calibration and control of bilirubinometers. These difficulties can be avoided by calibration with serum from healthy adults which is supplemented with unconjugated bilirubin. But this procedure is impracticable for most routine laboratories. Under certain preconditions, control samples, with bilirubin concentrations determined with correctly calibrated bilirubinometers or spectrophotometers, are also suitable as calibrators. This was established by determination of the bilirubin concentration of 16 different control samples, using both the reference method and correctly calibrated bilirubinometers or spectrophotometers in three or four specialist laboratories. This was also confirmed in several interlaboratory surveys, some involving up to 72 laboratories. The results of these investigations show that a control sample should be used for the calibration of a bilirubinometer only if it meets the following preconditions: 1. There should be no significant difference between the bilirubin values determined with the reference method and with a correctly calibrated spectrophotometer or bilirubinometer. 2. The bilirubin concentration should lie in the range 230-300 mumol/l. The photometric response of bilirubinometers has a limited linear range, so that analytical results greater than 300 mumol/l must be rated as basically unreliable.

  6. Preliminary evaluation of a Neutron Calibration Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Talysson S.; Neves, Lucio P.; Perini, Ana P.; Sanches, Matias P.; Mitake, Malvina B.; Caldas, Linda V.E., E-mail: talvarenga@ipen.br, E-mail: lpneves@ipen.br, E-mail: aperini@ipen.br, E-mail: msanches@ipen.br, E-mail: mbmitake@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Federico, Claudio A., E-mail: claudiofederico@ieav.cta.br [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil). Dept. de Ciencia e Tecnologia Aeroespacial

    2013-07-01

    In the past few years, Brazil and several other countries in Latin America have experimented a great demand for the calibration of neutron detectors, mainly due to the increase in oil prospection and extraction. The only laboratory for calibration of neutron detectors in Brazil is localized at the Institute for Radioprotection and Dosimetry (IRD/CNEN), Rio de Janeiro, which is part of the IAEA SSDL network. This laboratory is the national standard laboratory in Brazil. With the increase in the demand for the calibration of neutron detectors, there is a need for another calibration services. In this context, the Calibration Laboratory of IPEN/CNEN, Sao Paulo, which already offers calibration services of radiation detectors with standard X, gamma, beta and alpha beams, has recently projected a new calibration laboratory for neutron detectors. In this work, the ambient equivalent dose rate (H⁎(10)) was evaluated in several positions inside and around this laboratory, using Monte Carlo simulation (MCNP5 code), in order to verify the adequateness of the shielding. The obtained results showed that the shielding is effective, and that this is a low-cost methodology to improve the safety of the workers and evaluate the total staff workload. (author)

  7. Calibration Errors in Interferometric Radio Polarimetry

    Science.gov (United States)

    Hales, Christopher A.

    2017-08-01

    Residual calibration errors are difficult to predict in interferometric radio polarimetry because they depend on the observational calibration strategy employed, encompassing the Stokes vector of the calibrator and parallactic angle coverage. This work presents analytic derivations and simulations that enable examination of residual on-axis instrumental leakage and position-angle errors for a suite of calibration strategies. The focus is on arrays comprising alt-azimuth antennas with common feeds over which parallactic angle is approximately uniform. The results indicate that calibration schemes requiring parallactic angle coverage in the linear feed basis (e.g., the Atacama Large Millimeter/submillimeter Array) need only observe over 30°, beyond which no significant improvements in calibration accuracy are obtained. In the circular feed basis (e.g., the Very Large Array above 1 GHz), 30° is also appropriate when the Stokes vector of the leakage calibrator is known a priori, but this rises to 90° when the Stokes vector is unknown. These findings illustrate and quantify concepts that were previously obscure rules of thumb.

  8. Beyond fossil calibrations: Realities of molecular clock practices in evolutionary biology

    Directory of Open Access Journals (Sweden)

    Christy Anna Hipsley

    2014-05-01

    Full Text Available Molecular-based divergence dating methods, or molecular clocks, are the primary neontological tool for estimating the temporal origins of clades. While the appropriate use of vertebrate fossils as external clock calibrations has stimulated heated discussions in the paleontological community, less attention has been given to the quality and implementation of other calibration types. In lieu of appropriate fossils, many studies rely on alternative sources of age constraints based on geological events, substitution rates and heterochronous sampling, as well as dates secondarily derived from previous analyses. To illustrate the breadth and frequency of calibration types currently employed, we conducted a literature survey of over 600 articles published from 2007 to 2013. Over half of all analyses implemented one or more fossil dates as constraints, followed by geological events and secondary calibrations (15% each. Vertebrate taxa were subjects of nearly half of all studies, while invertebrates and plants together accounted for 43%, followed by viruses, protists and fungi (3% each. Current patterns in calibration practices were disproportionate to the number of discussions on their proper use, particularly regarding plants and secondarily derived dates, which are both relatively neglected. Based on our survey, we provide a comprehensive overview of the latest approaches in clock calibration, and outline strengths and weaknesses associated with each. This critique should serve as a call to action for researchers across multiple communities, particularly those working on clades for which fossil records are poor, to develop their own guidelines regarding selection and implementation of alternative calibration types. This issue is particularly relevant now, as time-calibrated phylogenies are used for more than dating evolutionary origins, but often serve as the backbone of investigations into biogeography, diversity dynamics and rates of phenotypic

  9. SMAP RADAR Processing and Calibration

    Science.gov (United States)

    West, R. D.; Jaruwatanadilok, S.; Kwoun, O.; Chaubell, M. J.

    2013-12-01

    The Soil Moisture Active Passive (SMAP) mission uses L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Model sensitivities translate the soil moisture accuracy to a radar backscatter accuracy of 1 dB at 3 km resolution and a brightness temperature accuracy of 1.3 K at 40 km resolution. This presentation will describe the level 1 radar processing and calibration challenges and the choices made so far for the algorithms and software implementation. To obtain the desired high spatial resolution the level 1 radar ground processor employs synthetic aperture radar (SAR) imaging techniques. Part of the challenge of the SMAP data processing comes from doing SAR imaging on a conically scanned system with rapidly varying squint angles. The radar echo energy will be divided into range/Doppler bins using time domain processing algorithms that can easily follow the varying squint angle. For SMAP, projected range resolution is about 250 meters, while azimuth resolution varies from 400 meters to 1.2 km. Radiometric calibration of the SMAP radar means measuring, characterizing, and where necessary correcting the gain and noise contributions from every part of the system from the antenna radiation pattern all the way to the ground processing algorithms. The SMAP antenna pattern will be computed using an accurate antenna model, and then validated post-launch using homogeneous external targets such as the Amazon rain forest to look for uncorrected gain variation. Noise subtraction is applied after image processing using measurements from a noise only channel. Variations of the internal electronics are tracked by a loopback measurement which will capture most of the time and temperature variations of the transmit power and receiver gain. Long-term variations of system performance due to component aging will be tracked and corrected using stable external reference

  10. Digital breast tomosynthesis geometry calibration

    Science.gov (United States)

    Wang, Xinying; Mainprize, James G.; Kempston, Michael P.; Mawdsley, Gordon E.; Yaffe, Martin J.

    2007-03-01

    Digital Breast Tomosynthesis (DBT) is a 3D x-ray technique for imaging the breast. The x-ray tube, mounted on a gantry, moves in an arc over a limited angular range around the breast while 7-15 images are acquired over a period of a few seconds. A reconstruction algorithm is used to create a 3D volume dataset from the projection images. This procedure reduces the effects of tissue superposition, often responsible for degrading the quality of projection mammograms. This may help improve sensitivity of cancer detection, while reducing the number of false positive results. For DBT, images are acquired at a set of gantry rotation angles. The image reconstruction process requires several geometrical factors associated with image acquisition to be known accurately, however, vibration, encoder inaccuracy, the effects of gravity on the gantry arm and manufacturing tolerances can produce deviations from the desired acquisition geometry. Unlike cone-beam CT, in which a complete dataset is acquired (500+ projections over 180°), tomosynthesis reconstruction is challenging in that the angular range is narrow (typically from 20°-45°) and there are fewer projection images (~7-15). With such a limited dataset, reconstruction is very sensitive to geometric alignment. Uncertainties in factors such as detector tilt, gantry angle, focal spot location, source-detector distance and source-pivot distance can produce several artifacts in the reconstructed volume. To accurately and efficiently calculate the location and angles of orientation of critical components of the system in DBT geometry, a suitable phantom is required. We have designed a calibration phantom for tomosynthesis and developed software for accurate measurement of the geometric parameters of a DBT system. These have been tested both by simulation and experiment. We will present estimates of the precision available with this technique for a prototype DBT system.

  11. Interferometric Calibration with Natural Distributed Targets

    DEFF Research Database (Denmark)

    Dall, Jørgen; Christensen, Erik Lintz

    2002-01-01

    Cross-calibration is a fully automated algorithm for calibration of interferometric synthetic aperture radar (IFSAR) data. It has been developed for single-pass interferometry, but the principles may be applicable to multi-pass interferometry, too. The algorithm is based on natural distributed ta....... The algorithm appears to be fairly robust with respect to the terrain type. However, the result of the calibration may deteriorate if the terrain elevation, as measured with the SAR, changes systematically with the incidence angle or the aspect angle....

  12. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  13. Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Yordanova, Ginka

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  14. Astronomical calibration of the Maastrichtian (Late Cretaceous)

    DEFF Research Database (Denmark)

    Husson, Dorothée; Galbrun, Bruno; Laskar, Jacques

    2011-01-01

    Recent improvements to astronomical modeling of the Solar System have contributed to important refinements of the Cenozoic time scale through astronomical calibration of sedimentary series. We extend this astronomical calibration into the Cretaceous, on the base of the 405 ka orbital eccentricity...... of each magnetochron from C32r.2r to C29n are inferred by cycle counting. Astronomical calibrations of Maastrichtian sedimentary series are proposed, based on the 405 ka eccentricity variation according to the most recent astronomical solution La2010a. Two different ages are suggested for the K...

  15. 1% calibration errors in MQY magnets

    CERN Document Server

    Bach, T; Langner, A; Levinsen, Y; McAteer, M; Maclean, E H; Persson, T; Skowronski, P; Tomás, R; Todesco, E; White, S

    2013-01-01

    Errors in the range of 1% have been observed for the MQY magnets in beam-based measurements. Furthermore, inconsistencies have been observed when comparing previous magnetic measurements to the LHC LSA database. After a revision, new calibration data have been extracted and were compared to the optics corrections that have been obtained from beam-based measurements. In 27-11-2012 a MD session has been performed to test these calibration data. This paper reports on the experimental verification of the new calibration data for the MQY quadrupole magnets.

  16. Planck 2015 results: V. LFI calibration

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Ashdown, M.

    2016-01-01

    We present a description of the pipeline used to calibrate the Planck Low Frequency Instrument (LFI) timelines into thermodynamic temperatures for the Planck 2015 data release, covering four years of uninterrupted operations. As in the 2013 data release, our calibrator is provided by the spin...... to the 2013 Planck data release, thus reducing the discrepancy with the power spectrum measured by WMAP. We estimate that the LFI calibration uncertainty is now at the level of 0.20% for the 70 GHz map, 0.26% for the 44 GHz map, and 0.35% for the 30 GHz map. We provide a detailed description of the impact...

  17. MSSC: Multi-Source Self-Calibration

    Science.gov (United States)

    Radcliffe, Jack F.

    2017-09-01

    Multi-Source Self-Calibration (MSSC) provides direction-dependent calibration to standard phase referencing. The code combines multiple faint sources detected within the primary beam to derive phase corrections. Each source has its CLEAN model divided into the visibilities which results in multiple point sources that are stacked in the uv plane to increase the S/N, thus permitting self-calibration. This process applies only to wide-field VLBI data sets that detect and image multiple sources within one epoch.

  18. Independent System Calibration of Sentinel-1B

    OpenAIRE

    Marco Schwerdt; Kersten Schmidt; Núria Tous Ramon; Patrick Klenk; Nestor Yague-Martinez; Pau Prats-Iraola; Manfred Zink; Dirk Geudtner

    2017-01-01

    Sentinel-1B is the second of two C-Band Synthetic Aperture Radar (SAR) satellites of the Sentinel-1 mission, launched in April 2016—two years after the launch of the first satellite, Sentinel-1A. In addition to the commissioning of Sentinel-1B executed by the European Space Agency (ESA), an independent system calibration was performed by the German Aerospace Center (DLR) on behalf of ESA. Based on an efficient calibration strategy and the different calibration procedures already developed and...

  19. Prospective, Multi-Center Evaluation of the Beckman Coulter Prostate Health Index Using WHO Calibration

    Science.gov (United States)

    Loeb, Stacy; Sokoll, Lori J.; Broyles, Dennis L.; Bangma, Chris H.; van Schaik, Ron H.N.; Klee, George G.; Wei, John T.; Sanda, Martin G.; Partin, Alan W.; Slawin, Kevin M.; Marks, Leonard S.; Mizrahi, Isaac A.; Shin, Sanghyuk S.; Cruz, Amabelle B.; Chan, Daniel W.; Roberts, William L.; Catalona, William J.

    2014-01-01

    Purpose Reported prostate-specific antigen (PSA) values may differ substantially between assays with the Hybritech and World Health Organization (WHO) standardization. [-2]proPSA (p2PSA) and the Beckman Coulter prostate health index (phi) are newly approved serum markers, which are associated with prostate cancer risk and aggressiveness. Our objective was to study the influence of assay standardization on these markers. Materials and Methods PSA, % free PSA (%fPSA), and p2PSA were measured using the Hybritech calibration in 892 men undergoing prostate biopsy from a prospective multicenter study. Phi was calculated as: [p2PSA/ fPSA) × (square root of PSA)]. Performance characteristics of phi for prostate cancer detection were then determined using re-calculated WHO calibration PSA values. Results The median phi was significantly higher in men with prostate cancer compared to those with negative biopsies using the WHO values (47.4 vs 39.8, p<0.001). Phi offered improved discrimination of prostate cancer detection on biopsy (AUC 0.704) compared to %fPSA or total PSA using the WHO calibration. Conclusions Phi can be calculated using Hybritech or WHO standardized assays, and significantly improved the prediction of biopsy outcome over %fPSA or PSA alone. PMID:23206426

  20. Correlation between the genotoxicity endpoints measured by two different genotoxicity assays: comet assay and CBMN assay

    Directory of Open Access Journals (Sweden)

    Carina Ladeira

    2015-06-01

    The results concerning of positive findings by micronuclei and non significant ones by comet assay, are corroborated by Deng et al. (2005 study performed in workers occupationally exposed to methotrexate, also a cytostatic drug. According to Cavallo et al. (2009, the comet assay seems to be more suitable for the prompt evaluation of the genotoxic effects, for instance, of polycyclic aromatic hydrocarbons mixtures containing volatile substances, whereas the micronucleus test seems more appropriate to evaluate the effects of exposure to antineoplastic agents. However, there are studies that observed an increase in both the comet assay and the micronucleus test in nurses handling antineoplastic drugs, although statistical significance was only seen in the comet assay, quite the opposite of our results (Maluf & Erdtmann, 2000; Laffon et al. 2005.

  1. Calibration methods for rotating shadowband irradiometers and evaluation of calibration duration

    Science.gov (United States)

    Jessen, W.; Wilbert, S.; Nouri, B.; Geuder, N.; Fritz, H.

    2015-10-01

    Resource assessment for Concentrated Solar Power (CSP) needs accurate Direct Normal Irradiance (DNI) measurements. An option for such measurement campaigns are Rotating Shadowband Irradiometers (RSIs) with a thorough calibration. Calibration of RSIs and Si-sensors in general is complex because of the inhomogeneous spectral response of such sensors and incorporates the use of several correction functions. A calibration for a given atmospheric condition and air mass might not work well for a different condition. This paper covers procedures and requirements for two calibration methods for the calibration of Rotating Shadowband Irradiometers. The necessary duration of acquisition of test measurements is examined in regard to the site specific conditions at Plataforma Solar de Almeria (PSA) in Spain. Data sets of several long-term calibration periods from PSA are used to evaluate the deviation of results from calibrations with varying duration from the long-term result. The findings show that seasonal changes of environmental conditions are causing small but noticeable fluctuation of calibration results. Certain periods (i.e. November to January and April to May) show a higher likelihood of particularly adverse calibration results. These effects can partially be compensated by increasing the inclusions of measurements from outside these periods. Consequently, the duration of calibrations at PSA can now be selected depending on the time of the year in which measurements are commenced.

  2. World Health Organization International Standard To Harmonize Assays for Detection of Mycoplasma DNA.

    Science.gov (United States)

    Nübling, C Micha; Baylis, Sally A; Hanschmann, Kay-Martin; Montag-Lessing, Thomas; Chudy, Michael; Kreß, Julia; Ulrych, Ursula; Czurda, Stefan; Rosengarten, Renate

    2015-09-01

    Nucleic acid amplification technique (NAT)-based assays (referred to here as NAT assays) are increasingly used as an alternative to culture-based approaches for the detection of mycoplasma contamination of cell cultures. Assay features, like the limit of detection or quantification, vary widely between different mycoplasma NAT assays. Biological reference materials may be useful for harmonization of mycoplasma NAT assays. An international feasibility study included lyophilized preparations of four distantly related mycoplasma species (Acholeplasma laidlawii, Mycoplasma fermentans, M. orale, M. pneumoniae) at different concentrations which were analyzed by 21 laboratories using 26 NAT assays with a qualitative, semiquantitative, or quantitative design. An M. fermentans preparation was shown to decrease the interassay variation when used as a common reference material. The preparation was remanufactured and characterized in a comparability study, and its potency (in NAT-detectable units) across different NATs was determined. The World Health Organization (WHO) Expert Committee on Biological Standardization (ECBS) established this preparation to be the "1st World Health Organization international standard for mycoplasma DNA for nucleic acid amplification technique-based assays designed for generic mycoplasma detection" (WHO Tech Rep Ser 987:42, 2014) with a potency of 200,000 IU/ml. This WHO international standard is now available as a reference preparation for characterization of NAT assays, e.g., for determination of analytic sensitivity, for calibration of quantitative assays in a common unitage, and for defining regulatory requirements in the field of mycoplasma testing. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  3. HPS instrument calibration laboratory accreditation program

    Energy Technology Data Exchange (ETDEWEB)

    Masse, F.X; Eisenhower, E.H.; Swinth, K.L.

    1993-12-31

    The purpose of this paper is to provide an accurate overview of the development and structure of the program established by the Health Physics Society (HPS) for accrediting instrument calibration laboratories relative to their ability to accurately calibrate portable health physics instrumentation. The purpose of the program is to provide radiation protection professionals more meaningful direct and indirect access to the National Institute of Standards and Technology (NIST) national standards, thus introducing a means for improving the uniformity, accuracy, and quality of ionizing radiation field measurements. The process is designed to recognize and document the continuing capability of each accredited laboratory to accurately perform instrument calibration. There is no intent to monitor the laboratory to the extent that each calibration can be guaranteed by the program; this responsibility rests solely with the accredited laboratory.

  4. Calibration beads containing luminescent lanthanide ion complexes

    Science.gov (United States)

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  5. The 2007 ESO Instrument Calibration Workshop

    CERN Document Server

    Kaufer, Andreas; ESO Workshop

    2008-01-01

    The 2007 ESO Instrument Calibration workshop brought together more than 120 participants with the objective to a) foster the sharing of information, experience and techniques between observers, instrument developers and instrument operation teams, b) review the actual precision and limitations of the applied instrument calibration plans, and c) collect the current and future requirements by the ESO users. These present proceedings include the majority of the workshop’s contributions and document the status quo of instrument calibration at ESO in large detail. Topics covered are: Optical Spectro-Imagers, Optical Multi-Object Spectrographs, NIR and MIR Spectro-Imagers, High-Resolution Spectrographs, Integral Field Spectrographs, Adaptive Optics Instruments, Polarimetric Instruments, Wide Field Imagers, Interferometric Instruments as well as other crucial aspects such as data flow, quality control, data reduction software and atmospheric effects. It was stated in the workshop that "calibration is a life-long l...

  6. Preflight and Vicarious Calibration of Hyperspectral Imagers

    National Research Council Canada - National Science Library

    Thome, K. J; Biggar, S. F

    2007-01-01

    ... of the optical elements, image quality based on the MTF of the system, stray light, spectral response, polarization sensitivity, detector-to-detector radiometric calibration in both a relative and absolute sense...

  7. Low Power, Self Calibrated Vector Magnetometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR project investigates a novel approach to vector magnetometry based on high precision measurements of the total magnetic field. The calibration is...

  8. Bartolome Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17'S, 90 deg 33' W. Champion Island: 1 deg, 15'S, 90 deg, 05' W. Urvina Bay (Isabela...

  9. Calibration of the JEM-EUSO detector

    Directory of Open Access Journals (Sweden)

    Gorodetzky P.

    2013-06-01

    Full Text Available In order to unveil the mystery of ultra high energy cosmic rays (UHECRs, JEM-EUSO (Extreme Universe Space Observatory on-board Japan Experiment Module will observe extensive air showers induced by UHECRs from the International Space Station orbit with a huge acceptance. Calibration of the JEM-EUSO instrument, which consists of Fresnel optics and a focal surface detector with 5000 photomultipliers, is very important to discuss the origin of UHECRs precisely with the observed results. In this paper, the calibration before launch and on-orbit is described. The calibration before flight will be performed as precisely as possible with integrating spheres. In the orbit, the relative change of the performance will be checked regularly with on-board and on-ground light sources. The absolute calibration of photon detection efficiency may be performed with the moon, which is a stable light source in the nature.

  10. Computer Vision Assisted Virtual Reality Calibration

    Science.gov (United States)

    Kim, W.

    1999-01-01

    A computer vision assisted semi-automatic virtual reality (VR) calibration technology has been developed that can accurately match a virtual environment of graphically simulated three-dimensional (3-D) models to the video images of the real task environment.

  11. Calibration Systems of the ATLAS Tile Calorimeter

    CERN Document Server

    Lundberg, O

    2013-01-01

    TileCal is the hadronic calorimeter covering the most central region of the ATLAS experiment at the LHC. This sampling calorimeter uses iron plates as absorber and plastic scintillating tiles as the active material. A multi-faceted calibration system allows to monitor and equalize the calorimeter response at each stage of the signal production, from scintillation light to digitization. This calibration system is based on signal generation from different sources: a Cs radioactive source, laser light, charge injection and minimum bias events produced in proton-proton collisions. A brief description of the different TileCal calibration systems is given and the latest results on their performance in terms of calibration factors, linearity and stability are presented.

  12. Calibration systems of the ATLAS Tile Calorimeter

    CERN Document Server

    Lundberg, O; The ATLAS collaboration

    2012-01-01

    TileCal is the hadronic calorimeter covering the most central region of the ATLAS experiment at the LHC. This sampling calorimeter uses iron plates as absorber and plastic scintillating tiles as the active material. Scintillation light produced in the tiles is transmitted by wavelength shifting fibers to photomultiplier tubes (PMTs). The resulting electronic signals from the over 10000 PMTs are measured and digitized before being transferred to off-detector data-acquisition systems. A multi-faceted calibration system allows to monitor and equalize the calorimeter response at each stage of the signal production, from scintillation light to digitization. This calibration system is based on signal generation from different sources: a Cs radioactive source, laser light, charge injection and minimum bias events produced in proton-proton collisions. This talk presents a brief description of the different TileCal calibration systems and presents the latest results on their performance in terms of calibration factors...

  13. ARM Shortwave and Longwave Radiometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina; Webb, Craig

    2017-03-23

    This presentation provides a high-level overview of shortwave and longwave calibrations performed at the U.S. Department of Energy's Atmospheric Radiation Measurement program Southern Great Plains site.

  14. Calibration of pressure gauge for Cherenkov detector

    CERN Document Server

    Saponjic, Nevena

    2013-01-01

    Solartron/Hamilton pressure gauges are used to monitor the gas pressure in the particle beam detectors installed in the experimental areas. Here is description of the test bench for the calibration of these gauges in Labview.

  15. Calibration of electrical impedance tomography

    Energy Technology Data Exchange (ETDEWEB)

    Daily, W; Ramirez, A

    2000-05-01

    Over the past 10 years we have developed methods for imaging the electrical resistivity of soil and rock formations. These technologies have been called electrical resistance tomography of ERT (e.g. Daily and Owen, 1991). Recently we have been striving to extend this capability to include images of electric impedance--with a new nomenclature of electrical impedance tomography or EIT (Ramirez et al., 1999). Electrical impedance is simply a generalization of resistance. Whereas resistance is the zero frequency ratio of voltage and current, impedance includes both the magnitude and phase relationship between voltage and current at frequency. This phase and its frequency behavior is closely related to what in geophysics is called induced polarization or (Sumner, 1976). Why is this phase or IP important? IP is known to be related to many physical phenomena of importance so that image of IP will be maps of such things as mineralization and cation exchange IP (Marshall and Madden, 1959). Also, it is likely that IP, used in conjunction with resistivity, will yield information about the subsurface that can not be obtained by either piece of information separately. In order to define the accuracy of our technologies to image impedance we have constructed a physical model of known impedance that can be used as a calibration standard. It consists of 616 resistors, along with some capacitors to provide the reactive response, arranged in a three dimensional structure as in figure 1. Figure 2 shows the construction of the network and defines the coordinate system used to describe it. This network of components is a bounded and discrete version of the unbounded and continuous medium with which we normally work (the subsurface). The network has several desirable qualities: (1) The impedance values are known (to the accuracy of the component values). (2) The component values and their 3D distribution is easily controlled. (3) Error associated with electrode noise is eliminated. (4

  16. Lidar to lidar calibration phase 1

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents a feasibility study of a lidar to lidar (L2L) calibration procedure. Phase one of the project was conducted at Høvsøre, Denmark. Two windcubes were placed next to the 116m met mast and different methods were applied to obtain the sensing height error of the lidars. The purpose...... is to find the most consistent method and use it in a potential lidar to lidar calibration procedure....

  17. Absolute Radiometric Calibration of KOMPSAT-3A

    OpenAIRE

    Ahn, H. Y.; Shin, D. Y.; Kim, J. S.; Seo, D. C.; Choi, C. U.

    2016-01-01

    This paper presents a vicarious radiometric calibration of the Korea Multi-Purpose Satellite-3A (KOMPSAT-3A) performed by the Korea Aerospace Research Institute (KARI) and the Pukyong National University Remote Sensing Group (PKNU RSG) in 2015.The primary stages of this study are summarized as follows: (1) A field campaign to determine radiometric calibrated target fields was undertaken in Mongolia and South Korea. Surface reflectance data obtained in the campaign were input to a rad...

  18. Calibration and Rating of Photovoltaics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Emery, K.

    2012-06-01

    Rating the performance of photovoltaic (PV) modules is critical to determining the cost per watt, and efficiency is useful to assess the relative progress among PV concepts. Procedures for determining the efficiency for PV technologies from 1-sun to low concentration to high concentration are discussed. We also discuss the state of the art in primary and secondary calibration of PV reference cells used by calibration laboratories around the world. Finally, we consider challenges to rating PV technologies and areas for improvement.

  19. Calibration with near-continuous spectral measurements

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Rasmussen, Michael; Madsen, Henrik

    2001-01-01

    In chemometrics traditional calibration in case of spectral measurements express a quantity of interest (e.g. a concentration) as a linear combination of the spectral measurements at a number of wavelengths. Often the spectral measurements are performed at a large number of wavelengths and in thi...... by an example in which the octane number of gasoline is related to near infrared spectral measurements. The performance is found to be much better that for the traditional calibration methods....

  20. Freehand ultrasound calibration: phantom versus tracked pointer

    Science.gov (United States)

    Welch, Mattea; Andrea, Jennifer; Ungi, Tamas; Fichtinger, Gabor

    2013-03-01

    PURPOSE: Ultrasound-guided tracked navigation requires spatial calibration between the ultrasound beam and the tracker. We examined the reproducibility and accuracy of two popular open source calibration methods1 with a handheld linear ultrasound transducer. METHODS: A total of 10 calibrations were performed using (1) a double N-wire phantom with automatic image segmentation and registration; (2) and registration of landmark points collected with a tracked pointer. Reproducibility and accuracy were characterized by comparing the resulting transformation matrices, and by comparing ground truth landmark points. RESULTS: Transformation matrices calculated with an N-wire phantom showed a variance of X: 0.02 mm (in the direction of sound propagation), Y: 0.03 mm (in the direction of transducer elements) and Z: 0.21 mm (in the elevation direction). Transformation matrices obtained with tracked pointer showed a variance of X: 0.1 mm, Y: 0.10 mm and Z: 0.43 mm. Calibration accuracy was tested with ground truth cross wire points. The N-wire phantom provided a calibration with a distance from ground truth of X: 2.44 +/- 1.44 mm, Y: 1.21 +/- 0.88 mm, and Z: 1.12 +/- 0.82 mm. Tracked pointer calibration had a distance from the ground truth of X: 0.23 +/- 0.16 mm, Y: 0.62 +/- 0.31 mm, and Z: 0.45 +/- 0.33 mm. Distance from ground truth was significantly less (ptracked pointer method in all directions. CONCLUSION: Calibration using a tracked pointer had a slightly greater variance; however it showed better accuracy over calibrations calculated with N-wire phantoms.

  1. Calibration of Photon Sources for Brachytherapy

    Science.gov (United States)

    Rijnders, Alex

    Source calibration has to be considered an essential part of the quality assurance program in a brachytherapy department. Not only it will ensure that the source strength value used for dose calculation agrees within some predetermined limits to the value stated on the source certificate, but also it will ensure traceability to international standards. At present calibration is most often still given in terms of reference air kerma rate, although calibration in terms of absorbed dose to water would be closer to the users interest. It can be expected that in a near future several standard laboratories will be able to offer this latter service, and dosimetry protocols will have to be adapted in this way. In-air measurement using ionization chambers (e.g. a Baldwin—Farmer ionization chamber for 192Ir high dose rate HDR or pulsed dose rate PDR sources) is still considered the method of choice for high energy source calibration, but because of their ease of use and reliability well type chambers are becoming more popular and are nowadays often recommended as the standard equipment. For low energy sources well type chambers are in practice the only equipment available for calibration. Care should be taken that the chamber is calibrated at the standard laboratory for the same source type and model as used in the clinic, and using the same measurement conditions and setup. Several standard laboratories have difficulties to provide these calibration facilities, especially for the low energy seed sources (125I and 103Pd). Should a user not be able to obtain properly calibrated equipment to verify the brachytherapy sources used in his department, then at least for sources that are replaced on a regular basis, a consistency check program should be set up to ensure a minimal level of quality control before these sources are used for patient treatment.

  2. Fibre optic power meter calibration uncertainties

    CSIR Research Space (South Africa)

    Nel, M

    2010-06-01

    Full Text Available 2010 - EngineerIT Technical Fibre optic power meter calibration uncertainties by Mariesa Nel, NMISA and Bertus Theron, CSIR-Defence, Peace, Safety and Security This article discusses the determination of uncertainty contributions when performing a... and Instrumentation News EngineerIT - June 2010 41 Most of these uncertainty contributions can either be obtained from a calibration certificate, specifications, or empirical measurements. In the next two sections detail are given on how to determine...

  3. Calibration and monitoring for crystal calorimetry

    CERN Document Server

    Zhu, Ren Yuan

    2005-01-01

    Crystal calorimetry provides excellent energy resolution in high energy and nuclear physics. The light output of heavy crystal scintillators, however, suffers from not negligible damage in radiation environment. A precision calibration and monitoring thus is crucial for maintaining crystal precision in situ. The performance of calibration and monitoring approaches used by BaBar, CLEO and L3 experiments are presented. The design and construction of a laser- based light monitoring system for CMS PWO calorimeter is also discussed.

  4. pH sensor calibration procedure

    OpenAIRE

    Artero Delgado, Carola; Nogueras Cervera, Marc; Manuel Lázaro, Antonio; Prat Tasias, Jordi; Prat Farran, Joana d'Arc

    2013-01-01

    This paper describes the calibration of pH sensor located at the OBSEA marine Observatory. This instrument is based on an industrial pH electrode that is connected to a CTD instrument (Conductivity, Temperature, and Depth ). The calibration of the pH sensor has been done using a high precision spectrophotometer pH meter from Institute of Marine Sciences (ICM), and in this way it has been obtained a numerical function for the p H sensor propor...

  5. Spitzer/JWST Cross Calibration: IRAC Observations of Potential Calibrators for JWST

    Science.gov (United States)

    Carey, Sean J.; Gordon, Karl D.; Lowrance, Patrick; Ingalls, James G.; Glaccum, William J.; Grillmair, Carl J.; E Krick, Jessica; Laine, Seppo J.; Fazio, Giovanni G.; Hora, Joseph L.; Bohlin, Ralph

    2017-06-01

    We present observations at 3.6 and 4.5 microns using IRAC on the Spitzer Space Telescope of a set of main sequence A stars and white dwarfs that are potential calibrators across the JWST instrument suite. The stars range from brightnesses of 4.4 to 15 mag in K band. The calibration observations use a similar redundancy to the observing strategy for the IRAC primary calibrators (Reach et al. 2005) and the photometry is obtained using identical methods and instrumental photometric corrections as those applied to the IRAC primary calibrators (Carey et al. 2009). The resulting photometry is then compared to the predictions based on spectra from the CALSPEC Calibration Database (http://www.stsci.edu/hst/observatory/crds/calspec.html) and the IRAC bandpasses. These observations are part of an ongoing collaboration between IPAC and STScI investigating absolute calibration in the infrared.

  6. "Calibration-on-the-spot'': How to calibrate an EMCCD camera from its images

    DEFF Research Database (Denmark)

    Mortensen, Kim; Flyvbjerg, Henrik

    In localization-based microscopy, super-resolution is obtained by analyzing isolated diffraction-limited spots imaged, typically, with EMCCD cameras. To compare experiments and calculate localization precision, the photon-to-signal amplification factor is needed but unknown without a calibration...... of the camera. Here we show how this can be done post festum from just a recorded image. We demonstrate this (i) theoretically, mathematically, (ii) by analyzing images recorded with an EMCCD camera, and (iii) by analyzing simulated EMCCD images for which we know the true values of parameters. In summary, our...... method of calibration-on-the-spot allows calibration of a camera with unknown settings from old images on file, with no other info needed. Consequently, calibration-on-the-spot also makes future camera calibrations before and after measurements unnecessary, because the calibration is encoded in recorded...

  7. Herschel SPIRE FTS relative spectral response calibration

    Science.gov (United States)

    Fulton, Trevor; Hopwood, Rosalind; Baluteau, Jean-Paul; Benielli, Dominique; Imhof, Peter; Lim, Tanya; Lu, Nanyao; Marchili, Nicola; Naylor, David; Polehampton, Edward; Swinyard, Bruce; Valtchanov, Ivan

    2014-07-01

    Herschel/SPIRE Fourier transform spectrometer (FTS) observations contain emission from both the Herschel Telescope and the SPIRE Instrument itself, both of which are typically orders of magnitude greater than the emission from the astronomical source, and must be removed in order to recover the source spectrum. The effects of the Herschel Telescope and the SPIRE Instrument are removed during data reduction using relative spectral response calibration curves and emission models. We present the evolution of the methods used to derive the relative spectral response calibration curves for the SPIRE FTS. The relationship between the calibration curves and the ultimate sensitivity of calibrated SPIRE FTS data is discussed and the results from the derivation methods are compared. These comparisons show that the latest derivation methods result in calibration curves that impart a factor of between 2 and 100 less noise to the overall error budget, which results in calibrated spectra for individual observations whose noise is reduced by a factor of 2-3, with a gain in the overall spectral sensitivity of 23 % and 21 % for the two detector bands, respectively.

  8. Activity Assays for Rhomboid Proteases.

    Science.gov (United States)

    Arutyunova, E; Strisovsky, K; Lemieux, M J

    2017-01-01

    Rhomboids are ubiquitous intramembrane serine proteases that are involved in various signaling pathways. This fascinating class of proteases harbors an active site buried within the lipid milieu. High-resolution structures of the Escherichia coli rhomboid GlpG with various inhibitors revealed the catalytic mechanism for rhomboid-mediated proteolysis; however, a quantitative characterization was lacking. Assessing an enzyme's catalytic parameters is important for understanding the details of its proteolytic reaction and regulatory mechanisms. To assay rhomboid protease activity, many challenges exist such as the lipid environment and lack of known substrates. Here, we summarize various enzymatic assays developed over the last decade to study rhomboid protease activity. We present detailed protocols for gel-shift and FRET-based assays, and calculation of KM and Vmax to measure catalytic parameters, using detergent solubilized rhomboids with TatA, the only known substrate for bacterial rhomboids, and the model substrate fluorescently labeled casein. © 2017 Elsevier Inc. All rights reserved.

  9. A comparison of INRs after local calibration of thromboplastin international sensitivity indexes.

    Science.gov (United States)

    McGlasson, David L

    2002-01-01

    There are approximately 300 reagent/instrument combinations for performing prothrombin times/international normalized ratios (PT/INR) in the United States. Manufacturers and laboratories continually struggle to ensure that the International Sensitivity Index (ISI) of their thromboplastin is accurate for assaying PT/INR. This study reports the feasibility of a new method to locally calibrate ISI of thromboplastin using the mechanical STA automated coagulation analyzer (Diagnostica-Stago Inc.) and two photo-optic coagulation analyzers, the BCS (Dade-Behring) and CA-540 (Sysmex). Neoplastine CI+ (CI+) (Diagnostica-Stago Inc); Thromboplastin C+ (TC+); Thromborel S (TRS); and Innovin (I) (Dade-Behring) were used in this study. A mean normal PT (MNPT) was determined for each reagent/instrument combination using samples from 25 normal individuals. Manufacturer instrument specific ISI values were not available for the STA with TC+, TRS and I. The CA540 had no ISI value for CI+ and the BCS system had no manufacturer assigned ISI values for TC+ and I; generic photo-optic and mechanical ISI manufacturer values were used for these two systems. Local on-site calibration was performed using frozen plasma calibrators to determine ISI values for each thromboplastin. Post-calibration, 95 patient samples were assayed for each reagent/instrument system combination using the manufacturer ISI and the local calibrated ISI to determine the INR result. Patients from whom samples were obtained included five with a lupus anticoagulant, 30 on heparin therapy, and 60 on coumadin therapy. Differences between manufacturer versus local calibrated ISI ranged from 0.9% to 18.9% for normal sample INRs and from 0.8% to 16.4% for patient sample INRs. The number (or proportion) of patient specimens with clinically significantly different INR values (>10.0% difference) ranged from zero for several reagent combinations to more than half (or >50.0%) of those tested for several other combinations. Our

  10. Calibration of reference KAP-meters at SSDL and cross calibration of clinical KAP-meters.

    Science.gov (United States)

    Hetland, Per O; Friberg, Eva G; Ovrebø, Kirsti M; Bjerke, Hans H

    2009-01-01

    In the summer of 2007 the secondary standard dosimetry laboratory (SSDL) in Norway established a calibration service for reference air-kerma product meter (KAP-meter). The air-kerma area product, P(KA), is a dosimetric quantity that can be directly related to the patient dose and used for risk assessment associated with different x-ray examinations. The calibration of reference KAP-meters at the SSDL gives important information on parameters influencing the calibration factor for different types of KAP-meters. The use of reference KAP-meters calibrated at the SSDL is an easy and reliable way to calibrate or verify the P(KA) indicated by the x-ray equipment out in the clinics. Twelve KAP-meters were calibrated at the SSDL by use of the substitution method at five diagnostic radiation qualities (RQRs). The calibration factors varied from 0.94 to 1.18. The energy response of the individual KAP-meters varied by a total of 20% between the different RQRs and the typical chamber transmission factors ranged from 0.78 to 0.91. It is important to use a calibrated reference KAP-meter and a harmonised calibration method in the P(KA) calibration in hospitals. The obtained uncertainty in the P(KA) readings is comparable with other calibration methods if the information in the calibration certificate is correct used, corrections are made and proper positioning of the KAP-chamber is performed. This will ensure a reliable estimate of the patient dose and a proper optimisation of conventional x-ray examinations and interventional procedures.

  11. Diversity Summit Presentation

    OpenAIRE

    Pratt-Clarke, Menah

    2017-01-01

    Key Message: Sustainable transformation is needed at Virginia Tech around diversity and inclusion Employers and Alumni recognize value of diversity and excellence VT needs to be a destination for the recruitment of a diverse workforce VT needs to be a destination for preparing leaders to serve in the spirit of community, diversity, and excellence

  12. Managing Workplace Diversity

    OpenAIRE

    Harold Andrew Patrick; Vincent Raj Kumar

    2012-01-01

    Diversity management is a process intended to create and maintain a positive work environment where the similarities and differences of individuals are valued. The literature on diversity management has mostly emphasized on organization culture; its impact on diversity openness; human resource management practices; institutional environments and organizational contexts to diversity-related pressures, expectations, requ...

  13. Forecast of physicochemical properties and chemical composition of gasoline from infrared spectra, using multivariate calibration; Previsao de propriedades fisico-quimicas e composicao quimica da gasolina a partir de espectros infravermelhos, utilizando calibracao multivariada

    Energy Technology Data Exchange (ETDEWEB)

    Cocco, Lilian Cristina; Yamamoto, Carlos Itsuo [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Lab. de Analise de Combustiveis Automotivos (LACAUTets)

    2008-07-01

    This work describes the attainment of mathematical models, applying multivariate calibration in infrared spectrum with ATR, from 128 gasoline samples with diverse chemical compositions, collected in a period of two and a half years. Infrared spectra had been used to assemble the input matrix for the modeling, whereas the standardized assays and gaseous chromatography had supplied the output matrices. Ninety samples were been used for training and 38 for testing. In order to calibrate chemical composition from chromatography, the techniques of mass spectrometry and chemical ionization were used to identify unknown substances and improve the fitting of the mathematical models. Two hundred and ninety substances were detected and identified, from which 100 were unknown. Six PLS/PCR models were attained to predict some properties as specific mass, Reid vapor pressure, T10, T50, T90 and PFE from distillation curve. Another six PLS/PCR models were attained to predict the amount of aromatics, paraffins, isoparaffins, naphthenes, olefins and oxygenates. In general, mathematical models were attained with good training fit, with correlation coefficients higher than 0,975 (T10) and reaching a maximum of 0,998 (naphthenes) and they are able to forecast an average chemical percentage and properties of interest from gasoline, with acceptable prediction errors. (author)

  14. Assessment of the integrity of compounds stored in assay-ready plates using a kinase sentinel assay.

    Science.gov (United States)

    Chen, Ada; Zhao, Xiaoning; Mercer, Laina; Su, Cheng; Zalameda, Leeanne; Liu, Yichin; Lembke, Amanda; Eastwood, Heather; Dang, Son; Oung, Thim; Xia, Xiaoyang; Young, Stephen W; Xiao, Shouhua; McCarter, John D

    2013-09-01

    Sentinel assays are a convenient adjunct to LC-MS purity assessment to monitor the integrity of compounds in pharmaceutical screening collections over time. To assess the stability of compounds stored both at room temperature and at -20°C in assay-ready plates that were either vacuum pack-sealed using a convenient industrial vacuum sealing method or individually sealed using conventional foil seals, a diverse collection of ~ 5,000 compounds was assayed using a robust biochemical kinase assay at intervals over a one year period. Assay results at each time point were compared to those of initial assay using a series of correlations of compound Percent of Control (POC) values as well as IC50 values of a subset of compounds in 200 nL or 500 nL plates. The fraction of hits in common between initial assays and assays at later time points ranged from 82% to 95% over one year and remained relatively constant over time with all storage temperatures or sealing methods tested. A majority of the hits that exhibited a consistent gradual trend to lower potency over one year storage were shifted to lower potency upon the rapid removal of DMSO solvent. Compound precipitation rather than compound decomposition is the likely reason for trends to lower potency for most such compounds over the storage period. Plates stored at room temperature featured a significantly higher fraction of hits that exhibited a trend to lower apparent potency than those stored at -20°C suggesting that this lower temperature is preferable for longer-term storage.

  15. Pulse-based internal calibration of polarimetric SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Skou, Niels; Christensen, Erik Lintz

    1994-01-01

    Internal calibration greatly diminishes the dependence on calibration target deployment compared to external calibration. Therefore the Electromagnetics Institute (EMI) at the Technical University of Denmark (TUD) has equipped its polarimetric SAR, EMISAR, with several calibration loops and devel......Internal calibration greatly diminishes the dependence on calibration target deployment compared to external calibration. Therefore the Electromagnetics Institute (EMI) at the Technical University of Denmark (TUD) has equipped its polarimetric SAR, EMISAR, with several calibration loops...... and developed a procedure for calibrating the entire system except a few passive components which must be measured in the laboratory. The calibration procedure has great potential as it takes into account the SAR point target response (PTR) unlike most other internal calibration schemes. However, it requires...

  16. Calibration methods for rotating shadowband irradiometers and optimizing the calibration duration

    Science.gov (United States)

    Jessen, Wilko; Wilbert, Stefan; Nouri, Bijan; Geuder, Norbert; Fritz, Holger

    2016-04-01

    Resource assessment for concentrated solar power (CSP) needs accurate direct normal irradiance (DNI) measurements. An option for such measurement campaigns is the use of thoroughly calibrated rotating shadowband irradiometers (RSIs). Calibration of RSIs and Si-sensors is complex because of the inhomogeneous spectral response of these sensors and incorporates the use of several correction functions. One calibration for a given atmospheric condition and air mass might not be suitable under different conditions. This paper covers procedures and requirements of two calibration methods for the calibration of rotating shadowband irradiometers. The necessary duration of acquisition of test measurements is examined with regard to the site-specific conditions at Plataforma Solar de Almería (PSA) in Spain. Seven data sets of long-term test measurements were collected. For each data set, calibration results of varying durations were compared to its respective long-term result. Our findings show that seasonal changes of environmental conditions are causing small but noticeable fluctuation of calibration results. Calibration results within certain periods (i.e. November to January and April to May) show a higher likelihood of deviation. These effects can partially be attenuated by including more measurements from outside these periods. Consequently, the duration of calibrations at PSA can now be selected depending on the time of year in which measurements commence.

  17. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

    Science.gov (United States)

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

    2013-09-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.

  18. Results from source-based and detector-based calibrations of a CLARREO calibration demonstration system

    Science.gov (United States)

    Angal, Amit; McCorkel, Joel; Thome, Kurt

    2016-09-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission is formulated to determine long-term climate trends using SI-traceable measurements. The CLARREO mission will include instruments operating in the reflected solar (RS) wavelength region from 320 nm to 2300 nm. The Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO and facilitates testing and evaluation of calibration approaches. The basis of CLARREO and SOLARIS calibration is the Goddard Laser for Absolute Measurement of Response (GLAMR) that provides a radiance-based calibration at reflective solar wavelengths using continuously tunable lasers. SI-traceability is achieved via detector-based standards that, in GLAMR's case, are a set of NIST-calibrated transfer radiometers. A portable version of the SOLARIS, Suitcase SOLARIS is used to evaluate GLAMR's calibration accuracies. The calibration of Suitcase SOLARIS using GLAMR agrees with that obtained from source-based results of the Remote Sensing Group (RSG) at the University of Arizona to better than 5% (k=2) in the 720-860 nm spectral range. The differences are within the uncertainties of the NIST-calibrated FEL lamp-based approach of RSG and give confidence that GLAMR is operating at Suitcase SOLARIS instrument also discussed and the next edition of the SOLARIS instrument (Suitcase SOLARIS- 2) is expected to provide an improved mechanism to further assess GLAMR and CLARREO calibration approaches.

  19. Slit-lamp calibration, crucial but neglected

    Directory of Open Access Journals (Sweden)

    Lutfah Rif’ati

    2013-05-01

    Full Text Available AbstrakLatar belakang: Kalibrasi berkala alat diagnostik sangat esensial untuk diagnosis yang akurat. Riset fasilitas kesehatan (Rifaskes 2011 mengumpulkan data termasuk kalibrasi lampu celah (slit-lamp pada sampel rumah sakit (RS di Indonesia. Tujuan analisis ialah untuk mengidentifikasi faktor dominan yang berpengaruh terhadap pelaksanaan kalibrasi berkala lampu celah di RS.Metode: Analisis memakai sebagian data Rifaskes 2011 di antara 442 RS yang menyediakan layanan kesehatan mata. Risiko relatif dipergunakan untuk menilai kemungkinan tidak dilakukannya kalibrasi lampu celah di RS.Hasil: Di antara 248 RS sampel yang memenuhi kriteria inklusi, hanya 25,8% RS yang melakukan kalibrasi lampu celah tepat waktu. Dibandingkan dengan rumah sakit yang dimiliki oleh Badan Usaha Milik Negara (BUMN, rumah sakit yang dimiliki lembaga lain memiliki risiko yang lebih tinggi tidak mengkalibrasi lampu celah. Menurut tipe RS, RS non-pendidikan dibandingkan dengan RS -pendidikan berisiko 40% lebih tinggi tidak mengkalibrasi lampu [risiko relatif suaian (RRa = 1,40; 95% interval kepercayaan (CI = 1,02-1,91].Kesimpulan: Kalibrasi tepat waktu lampu-celah masih menjadi masalah di sebagian besar RS. Dibandingkan dengan rumah sakit yang dimiliki oleh BUMN, rumah sakit yang dimiliki oleh instansi lain berisiko yang lebih tinggi tidak mengkalibrasi lampu celah. (Health Science Indones 2012;2:xx-xxKata kunci:kalibrasi, lampu celah, rumah sakitAbstractBackground: Periodical diagnostic tool calibration is essential for accurate diagnosis. Health Facilities Research (Rifaskes in 2011 collected data on the slit-lamp calibration of all registered general hospitals in Indonesia.Methods: Analysis using a part Rifaskes 2011 data among 442 hospitals that provide eye health services. Relative risk was used to assess the risk of performing calibration slit lamp.Results: Out of 442 hospitals, 248 hospitals met the inclusion study criteria, and only 25.8% calibrating the slit

  20. Chromosome aberration assays in Allium

    Energy Technology Data Exchange (ETDEWEB)

    Grant, W.F.

    1982-01-01

    The common onion (Allium cepa) is an excellent plant for the assay of chromosome aberrations after chemical treatment. Other species of Allium (A. cepa var. proliferum, A. carinatum, A. fistulosum and A. sativum) have also been used but to a much lesser extent. Protocols have been given for using root tips from either bulbs or seeds of Allium cepa to study the cytological end-points, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. It is considered that both mitotic and meiotic end-points should be used to a greater extent in assaying the cytogenetic effects of a chemical. From a literature survey, 148 chemicals are tabulated that have been assayed in 164 Allium tests for their clastogenic effect. Of the 164 assays which have been carried out, 75 are reported as giving a positive reaction, 49 positive and with a dose response, 1 positive and temperature-related, 9 borderline positive, and 30 negative; 76% of the chemicals gave a definite positive response. It is proposed that the Allium test be included among those tests routinely used for assessing chromosomal damage induced by chemicals.

  1. Exploration of new multivariate spectral calibration algorithms.

    Energy Technology Data Exchange (ETDEWEB)

    Van Benthem, Mark Hilary; Haaland, David Michael; Melgaard, David Kennett; Martin, Laura Elizabeth; Wehlburg, Christine Marie; Pell, Randy J. (The Dow Chemical Company, Midland, MI); Guenard, Robert D. (Merck & Co. Inc., West Point, PA)

    2004-03-01

    A variety of multivariate calibration algorithms for quantitative spectral analyses were investigated and compared, and new algorithms were developed in the course of this Laboratory Directed Research and Development project. We were able to demonstrate the ability of the hybrid classical least squares/partial least squares (CLSIPLS) calibration algorithms to maintain calibrations in the presence of spectrometer drift and to transfer calibrations between spectrometers from the same or different manufacturers. These methods were found to be as good or better in prediction ability as the commonly used partial least squares (PLS) method. We also present the theory for an entirely new class of algorithms labeled augmented classical least squares (ACLS) methods. New factor selection methods are developed and described for the ACLS algorithms. These factor selection methods are demonstrated using near-infrared spectra collected from a system of dilute aqueous solutions. The ACLS algorithm is also shown to provide improved ease of use and better prediction ability than PLS when transferring calibrations between near-infrared calibrations from the same manufacturer. Finally, simulations incorporating either ideal or realistic errors in the spectra were used to compare the prediction abilities of the new ACLS algorithm with that of PLS. We found that in the presence of realistic errors with non-uniform spectral error variance across spectral channels or with spectral errors correlated between frequency channels, ACLS methods generally out-performed the more commonly used PLS method. These results demonstrate the need for realistic error structure in simulations when the prediction abilities of various algorithms are compared. The combination of equal or superior prediction ability and the ease of use of the ACLS algorithms make the new ACLS methods the preferred algorithms to use for multivariate spectral calibrations.

  2. Determining vitamin D status: a comparison between commercially available assays.

    Directory of Open Access Journals (Sweden)

    Greta Snellman

    Full Text Available BACKGROUND: Vitamin D is not only important for bone health but can also affect the development of several non-bone diseases. The definition of vitamin D insufficiency by serum levels of 25-hydroxyvitamin D depends on the clinical outcome but might also be a consequence of analytical methods used for the definition. Although numerous 25-hydroxyvitamin D assays are available, their comparability is uncertain. We therefore aim to investigate the precision, accuracy and clinical consequences of differences in performance between three common commercially available assays. METHODOLOGY/PRINCIPAL FINDINGS: Serum 25-hydroxyvitamin D levels from 204 twins from the Swedish Twin Registry were determined with high-pressure liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS, a radioimmunoassay (RIA and a chemiluminescent immunoassay (CLIA. High inter-assay disagreement was found. Mean 25-hydroxyvitamin D levels were highest for the HPLC-APCI-MS technique (85 nmol/L, 95% CI 81-89, intermediate for RIA (70 nmol/L, 95% CI 66-74 and lowest with CLIA (60 nmol/L, 95% CI 56-64. Using a 50-nmol/L cut-off, 8% of the subjects were insufficient using HPLC-APCI-MS, 22% with RIA and 43% by CLIA. Because of the heritable component of 25-hydroxyvitamin D status, the accuracy of each method could indirectly be assessed by comparison of within-twin pair correlations. The strongest correlation was found for HPLC-APCI-MS (r = 0.7, intermediate for RIA (r = 0.5 and lowest for CLIA (r = 0.4. Regression analyses between the methods revealed a non-uniform variance (p<0.0001 depending on level of 25-hydroxyvitamin D. CONCLUSIONS/SIGNIFICANCE: There are substantial inter-assay differences in performance. The most valid method was HPLC-APCI-MS. Calibration between 25-hydroxyvitamin D assays is intricate.

  3. Forces applied during classical touch assays for Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Adam L Nekimken

    Full Text Available For decades, Caenorhabditis elegans roundworms have been used to study the sense of touch, and this work has been facilitated by a simple behavioral assay for touch sensation. To perform this classical assay, an experimenter uses an eyebrow hair to gently touch a moving worm and observes whether or not the worm reverses direction. We used two experimental approaches to determine the manner and moment of contact between the eyebrow hair tool and freely moving animals and the forces delivered by the classical assay. Using high-speed video (2500 frames/second, we found that typical stimulus delivery events include a brief moment when the hair is contact with the worm's body and not the agar substrate. To measure the applied forces, we measured forces generated by volunteers mimicking the classical touch assay by touching a calibrated microcantilever. The mean (61 μN and median forces (26 μN were more than ten times higher than the 2-μN force known to saturate the probability of evoking a reversal in adult C. elegans. We also considered the eyebrow hairs as an additional source of variation. The stiffness of the sampled eyebrow hairs varied between 0.07 and 0.41 N/m and was correlated with the free length of hair. Collectively, this work establishes that the classical touch assay applies enough force to saturate the probability of evoking reversals in adult C. elegans in spite of its variability among trials and experimenters and that increasing the free length of the hair can decrease the applied force.

  4. A multicentric evaluation of IDMS-traceable creatinine enzymatic assays.

    Science.gov (United States)

    Piéroni, Laurence; Delanaye, Pierre; Boutten, Anne; Bargnoux, Anne-Sophie; Rozet, Eric; Delatour, Vincent; Carlier, Marie-Christine; Hanser, Anne-Marie; Cavalier, Etienne; Froissart, Marc; Cristol, Jean-Paul

    2011-11-20

    Chronic kidney disease definition is based on glomerular filtration rate (GFR) estimations which are derived from creatinine-based equations. The accuracy of GFR estimation is thus largely dependent of those of serum creatinine assays. International recommendations highlight the need for traceable creatinine assays. The French Society of Clinical Biochemistry conducted a study for measuring accuracy of creatinine enzymatic methods. This evaluation involved 25 clinical laboratories. Creatinine was measured in serum pools ranging from 35.9±0.9 μmol/L to 174.5±3.1 μmol/L (IDMS determination) using 12 creatinine enzymatic methods. For all creatinine values greater than 74.4±1.4 μmol/L, the bias and imprecision did not exceed 5% and 5.9%, respectively. For the lowest value (35.9±0.9 μmol/L), the bias ranged from -1.8 to 9.9% (with one exception). At this level, the imprecision ranged from 1.9 to 7.8%. The true performances of the assays (couples of bias and relative standard deviation), were evaluated using Monte-Carlo simulations. Most of the assays fall within the maximum Total Error of 12% at all concentrations. This study demonstrates substantial improvements in the calibration, traceability and precision of the enzymatic methods, reaching the NKDEP recommendations. Moreover, most of these assays allowed accurate creatinine measurements for creatinine levels lower than 40 μmol/L. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. 40 CFR 1065.330 - Exhaust-flow calibration.

    Science.gov (United States)

    2010-07-01

    ... recommend that you use a calibration subsonic venturi or ultrasonic flow meter and simulate exhaust temperatures by incorporating a heat exchanger between the calibration meter and the exhaust-flow meter. If you... Exhaust-flow calibration. (a) Calibrate exhaust-flow meters upon initial installation. Follow the...

  6. Programmable and automatic calibrator for radio sources at 45 MHz

    Science.gov (United States)

    Aparici, J.; May, J.; Salas, F.; Ventura, J.

    1981-12-01

    The design, construction and operation of a standard calibrator is presented. The calibrator consists of saturated diodes controlled by an indirect feed-back system and a digital-to-analog converter. The advantages over similar designs are described, as for instance, high-resolution in the calibration scale, good stability, very fast calibrations, use of balanced electronic switches, etc.

  7. 40 CFR 89.320 - Carbon monoxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... carbon monoxide analyzer with either zero-grade air or zero-grade nitrogen. (3) Calibrate on each used... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration... Test Equipment Provisions § 89.320 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon...

  8. Capturing the Diversity in Lexical Diversity

    Science.gov (United States)

    Jarvis, Scott

    2013-01-01

    The range, variety, or diversity of words found in learners' language use is believed to reflect the complexity of their vocabulary knowledge as well as the level of their language proficiency. Many indices of lexical diversity have been proposed, most of which involve statistical relationships between types and tokens, and which ultimately…

  9. Statistical characterization of multiple-reaction monitoring mass spectrometry (MRM-MS assays for quantitative proteomics

    Directory of Open Access Journals (Sweden)

    Mani D R

    2012-11-01

    Full Text Available Abstract Multiple reaction monitoring mass spectrometry (MRM-MS with stable isotope dilution (SID is increasingly becoming a widely accepted assay for the quantification of proteins and peptides. These assays have shown great promise in relatively high throughput verification of candidate biomarkers. While the use of MRM-MS assays is well established in the small molecule realm, their introduction and use in proteomics is relatively recent. As such, statistical and computational methods for the analysis of MRM-MS data from proteins and peptides are still being developed. Based on our extensive experience with analyzing a wide range of SID-MRM-MS data, we set forth a methodology for analysis that encompasses significant aspects ranging from data quality assessment, assay characterization including calibration curves, limits of detection (LOD and quantification (LOQ, and measurement of intra- and interlaboratory precision. We draw upon publicly available seminal datasets to illustrate our methods and algorithms.

  10. Temporal transferability of soil moisture calibration equations

    Science.gov (United States)

    Rowlandson, Tracy L.; Berg, Aaron A.; Bullock, Paul R.; Hanis-Gervais, Krista; Ojo, E. RoTimi; Cosh, Michael H.; Powers, Jarrett; McNairn, Heather

    2018-01-01

    Several large-scale field campaigns have been conducted over the last 20 years that require accurate measurements of soil moisture conditions. These measurements are manually conducted using soil moisture probes which require calibration. The calibration process involves the collection of hundreds of soil moisture cores, which is extremely labor intensive. In 2012, a field campaign was conducted in southern Manitoba in which 55 fields were sampled and calibration equations were derived for each field. The Soil Moisture Active Passive Experiment 2016 (SMAPVEX16) was conducted in this same region, and 21 of the same fields were resampled. This study examines the temporal transferability of calibration equations between these two field campaigns. It was found that the larger range in soil moisture over which samples were collected in 2012 (average range 0.11-0.41 m3 m-3) generally resulted in lower errors when used in 2016 (average range 0.24-0.44 m3 m-3) than the equations derived in 2016 when used with data collected in 2012. Combining the data collected in 2012 and 2016 did not improve the errors, overall. These results suggest that the transfer of calibration equations from one year to the next is not recommended.

  11. Calibration of areal surface topography measuring instruments

    Science.gov (United States)

    Seewig, J.; Eifler, M.

    2017-06-01

    The ISO standards which are related to the calibration of areal surface topography measuring instruments are the ISO 25178-6xx series which defines the relevant metrological characteristics for the calibration of different measuring principles and the ISO 25178-7xx series which defines the actual calibration procedures. As the field of areal measurement is however not yet fully standardized, there are still open questions to be addressed which are subject to current research. Based on this, selected research results of the authors in this area are presented. This includes the design and fabrication of areal material measures. For this topic, two examples are presented with the direct laser writing of a stepless material measure for the calibration of the height axis which is based on the Abbott- Curve and the manufacturing of a Siemens star for the determination of the lateral resolution limit. Based on these results, as well a new definition for the resolution criterion, the small scale fidelity, which is still under discussion, is presented. Additionally, a software solution for automated calibration procedures is outlined.

  12. Planck 2015 results. V. LFI calibration

    Science.gov (United States)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaglia, P.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Christensen, P. R.; Colombi, S.; Colombo, L. P. L.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Knoche, J.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Novikov, D.; Novikov, I.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Peel, M.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Pierpaoli, E.; Pietrobon, D.; Pointecouteau, E.; Polenta, G.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renzi, A.; Rocha, G.; Romelli, E.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vassallo, T.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wehus, I. K.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-09-01

    We present a description of the pipeline used to calibrate the Planck Low Frequency Instrument (LFI) timelines into thermodynamic temperatures for the Planck 2015 data release, covering four years of uninterrupted operations. As in the 2013 data release, our calibrator is provided by the spin-synchronous modulation of the cosmic microwave background dipole, but we now use the orbital component, rather than adopting the Wilkinson Microwave Anisotropy Probe (WMAP) solar dipole. This allows our 2015 LFI analysis to provide an independent Solar dipole estimate, which is in excellent agreement with that of HFI and within 1σ (0.3% in amplitude) of the WMAP value. This 0.3% shift in the peak-to-peak dipole temperature from WMAP and a general overhaul of the iterative calibration code increases the overall level of the LFI maps by 0.45% (30 GHz), 0.64% (44 GHz), and 0.82% (70 GHz) in temperature with respect to the 2013 Planck data release, thus reducing the discrepancy with the power spectrum measured by WMAP. We estimate that the LFI calibration uncertainty is now at the level of 0.20% for the 70 GHz map, 0.26% for the 44 GHz map, and 0.35% for the 30 GHz map. We provide a detailed description of the impact of all the changes implemented in the calibration since the previous data release.

  13. Calibration Matters: Advances in Strapdown Airborne Gravimetry

    Science.gov (United States)

    Becker, D.

    2015-12-01

    Using a commercial navigation-grade strapdown inertial measurement unit (IMU) for airborne gravimetry can be advantageous in terms of cost, handling, and space consumption compared to the classical stable-platform spring gravimeters. Up to now, however, large sensor errors made it impossible to reach the mGal-level using such type IMUs as they are not designed or optimized for this kind of application. Apart from a proper error-modeling in the filtering process, specific calibration methods that are tailored to the application of aerogravity may help to bridge this gap and to improve their performance. Based on simulations, a quantitative analysis is presented on how much IMU sensor errors, as biases, scale factors, cross couplings, and thermal drifts distort the determination of gravity and the deflection of the vertical (DOV). Several lab and in-field calibration methods are briefly discussed, and calibration results are shown for an iMAR RQH unit. In particular, a thermal lab calibration of its QA2000 accelerometers greatly improved the long-term drift behavior. Latest results from four recent airborne gravimetry campaigns confirm the effectiveness of the calibrations applied, with cross-over accuracies reaching 1.0 mGal (0.6 mGal after cross-over adjustment) and DOV accuracies reaching 1.1 arc seconds after cross-over adjustment.

  14. Calibration of an ingestible temperature sensor.

    Science.gov (United States)

    Hunt, A P; Stewart, I B

    2008-11-01

    An ingestible telemetric sensor for measuring core body temperature is increasingly being utilized in occupational and athletic studies of heat strain. There is a need for a uniform method of calibrating these sensors in the scientific community in order to effectively compare the results of different researchers. The purpose of the present investigation was to determine and present such a calibration procedure. Sensors were placed in a water bath heated to nine discrete temperatures, and the recorded values were compared to that of a traceable thermometer. It was observed that sensor 2 recorded temperatures higher than sensors 1 and 3, and that all sensors were higher than the traceable thermometer, highlighting the need for a calibration procedure. The findings of this study suggest a number of recommendations for a calibration procedure including: (1) four water bath temperatures in the range of 33-41 degrees C should be utilized; (2) sensors should be immersed for a minimum of 4 min prior to taking a measurement; (3) a linear regression relating sensor temperature to a traceable thermometer is an appropriate method to adjust raw data. Switching the sensor off after calibration and reactivating it prior to ingestion will not influence the accuracy of temperature measurement.

  15. AUTOMATIC CALIBRATION METHOD FOR STEREOSCOPIC SYSTEM

    Directory of Open Access Journals (Sweden)

    A. V. Krasnyaschikh

    2014-07-01

    Full Text Available The paper deals with a new method of automatic calibration for stereoscopic system using test object. The idea of the method is to register stereoscopic image of specially selected reference object in the form of a chessboard with an extra field – a frame around chessboard – by means of two cameras. An algorithm implementing this method consists of seven stages: registration of set of images for a test object; image threshold filtering; recognition of test object by size and shape; background removal; position determination of four edge points; calibrating of the first and the second cameras; calibrating of stereoscopic system on the whole. The calibration process for the first and the second cameras and the system is performed by using a program developed by Jean-Yves Bouguet. Mathematical and physical modeling is done by means of two measuring cameras and MATLAB software package. Comparative error study for determination of the coordinates of test points in manual and automatic mode is carried out by modeling, as well as calibration error depending on the number of images obtained by stereo pair.

  16. Evolution of Altimetry Calibration and Future Challenges

    Science.gov (United States)

    Fu, Lee-Lueng; Haines, Bruce J.

    2012-01-01

    Over the past 20 years, altimetry calibration has evolved from an engineering-oriented exercise to a multidisciplinary endeavor driving the state of the art. This evolution has been spurred by the developing promise of altimetry to capture the large-scale, but small-amplitude, changes of the ocean surface containing the expression of climate change. The scope of altimeter calibration/validation programs has expanded commensurately. Early efforts focused on determining a constant range bias and verifying basic compliance of the data products with mission requirements. Contemporary investigations capture, with increasing accuracies, the spatial and temporal characteristics of errors in all elements of the measurement system. Dedicated calibration sites still provide the fundamental service of estimating absolute bias, but also enable long-term monitoring of the sea-surface height and constituent measurements. The use of a network of island and coastal tide gauges has provided the best perspective on the measurement stability, and revealed temporal variations of altimeter measurement system drift. The cross-calibration between successive missions provided fundamentally new information on the performance of altimetry systems. Spatially and temporally correlated errors pose challenges for future missions, underscoring the importance of cross-calibration of new measurements against the established record.

  17. Calibration-on-the-spot”: How to calibrate an EMCCD camera from its images

    DEFF Research Database (Denmark)

    Mortensen, Kim; Flyvbjerg, Henrik

    2016-01-01

    In order to count photons with a camera, the camera must be calibrated. Photon counting is necessary, e.g., to determine the precision of localization-based super-resolution microscopy. Here we present a protocol that calibrates an EMCCD camera from information contained in isolated, diffraction...

  18. NuSTAR ground calibration: The Rainwater Memorial Calibration Facility (RaMCaF)

    DEFF Research Database (Denmark)

    Brejnholt, Nicolai; Christensen, Finn Erland; Jakobsen, Anders Clemen

    2011-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing hard X-ray (5-80 keV ) telescope to orbit. The ground calibration of the three flight optics was carried out at the Rainwater Memorial Calibration Facility (RaMCaF) built...

  19. Simultaneous calibration phantom commission and geometry calibration in cone beam CT

    Science.gov (United States)

    Xu, Yuan; Yang, Shuai; Ma, Jianhui; Li, Bin; Wu, Shuyu; Qi, Hongliang; Zhou, Linghong

    2017-09-01

    Geometry calibration is a vital step for describing the geometry of a cone beam computed tomography (CBCT) system and is a prerequisite for CBCT reconstruction. In current methods, calibration phantom commission and geometry calibration are divided into two independent tasks. Small errors in ball-bearing (BB) positioning in the phantom-making step will severely degrade the quality of phantom calibration. To solve this problem, we propose an integrated method to simultaneously realize geometry phantom commission and geometry calibration. Instead of assuming the accuracy of the geometry phantom, the integrated method considers BB centers in the phantom as an optimized parameter in the workflow. Specifically, an evaluation phantom and the corresponding evaluation contrast index are used to evaluate geometry artifacts for optimizing the BB coordinates in the geometry phantom. After utilizing particle swarm optimization, the CBCT geometry and BB coordinates in the geometry phantom are calibrated accurately and are then directly used for the next geometry calibration task in other CBCT systems. To evaluate the proposed method, both qualitative and quantitative studies were performed on simulated and realistic CBCT data. The spatial resolution of reconstructed images using dental CBCT can reach up to 15 line pair cm-1. The proposed method is also superior to the Wiesent method in experiments. This paper shows that the proposed method is attractive for simultaneous and accurate geometry phantom commission and geometry calibration.

  20. Radiometer calibration methods and resulting irradiance differences: Radiometer calibration methods and resulting irradiance differences

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron [National Renewable Energy Laboratory, Golden CO 80401 USA; Sengupta, Manajit [National Renewable Energy Laboratory, Golden CO 80401 USA; Andreas, Afshin [National Renewable Energy Laboratory, Golden CO 80401 USA; Reda, Ibrahim [National Renewable Energy Laboratory, Golden CO 80401 USA; Robinson, Justin [GroundWork Renewables Inc., Logan UT 84321 USA

    2016-10-07

    Accurate solar radiation measured by radiometers depends on instrument performance specifications, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions. This study addresses the effect of different calibration methodologies and resulting differences provided by radiometric calibration service providers such as the National Renewable Energy Laboratory (NREL) and manufacturers of radiometers. Some of these methods calibrate radiometers indoors and some outdoors. To establish or understand the differences in calibration methodologies, we processed and analyzed field-measured data from radiometers deployed for 10 months at NREL's Solar Radiation Research Laboratory. These different methods of calibration resulted in a difference of +/-1% to +/-2% in solar irradiance measurements. Analyzing these differences will ultimately assist in determining the uncertainties of the field radiometer data and will help develop a consensus on a standard for calibration. Further advancing procedures for precisely calibrating radiometers to world reference standards that reduce measurement uncertainties will help the accurate prediction of the output of planned solar conversion projects and improve the bankability of financing solar projects.

  1. Simultaneous calibration phantom commission and geometry calibration in cone beam CT.

    Science.gov (United States)

    Xu, Yuan; Yang, Shuai; Ma, Jianhui; Li, Bin; Wu, Shuyu; Qi, Hongliang; Zhou, Linghong

    2017-08-09

    Geometry calibration is a vital step for describing the geometry of a cone beam computed tomography (CBCT) system and is a prerequisite for CBCT reconstruction. In current methods, calibration phantom commission and geometry calibration are divided into two independent tasks. Small errors in ball-bearing (BB) positioning in the phantom-making step will severely degrade the quality of phantom calibration. To solve this problem, we propose an integrated method to simultaneously realize geometry phantom commission and geometry calibration. Instead of assuming the accuracy of the geometry phantom, the integrated method considers BB centers in the phantom as an optimized parameter in the workflow. Specifically, an evaluation phantom and the corresponding evaluation contrast index are used to evaluate geometry artifacts for optimizing the BB coordinates in the geometry phantom. After utilizing particle swarm optimization, the CBCT geometry and BB coordinates in the geometry phantom are calibrated accurately and are then directly used for the next geometry calibration task in other CBCT systems. To evaluate the proposed method, both qualitative and quantitative studies were performed on simulated and realistic CBCT data. The spatial resolution of reconstructed images using dental CBCT can reach up to 15 line pair cm-1. The proposed method is also superior to the Wiesent method in experiments. This paper shows that the proposed method is attractive for simultaneous and accurate geometry phantom commission and geometry calibration.

  2. Evaluation of molecular assays for identification Campylobacter fetus species and subspecies and development of a C. fetus specific real-time PCR assay.

    Science.gov (United States)

    van der Graaf-van Bloois, Linda; van Bergen, Marcel A P; van der Wal, Fimme J; de Boer, Albert G; Duim, Birgitta; Schmidt, Tracy; Wagenaar, Jaap A

    2013-10-01

    Phenotypic differentiation between Campylobacter fetus (C. fetus) subspecies fetus and C. fetus subspecies venerealis is hampered by poor reliability and reproducibility of biochemical assays. AFLP (amplified fragment length polymorphism) and MLST (multilocus sequence typing) are the molecular standards for C. fetus subspecies identification, but these methods are laborious and expensive. Several PCR assays for C. fetus subspecies identification have been described, but a reliable comparison of these assays is lacking. The aim of this study was to evaluate the most practical and routinely implementable published PCR assays designed for C. fetus species and subspecies identification. The sensitivity and specificity of the assays were calculated by using an extensively characterized and diverse collection of C. fetus strains. AFLP and MLST identification were used as reference. Two PCR assays were able to identify C. fetus strains correctly at species level. The C. fetus species identification target, gene nahE, of one PCR assay was used to develop a real-time PCR assay with 100% sensitivity and 100% specificity, but the development of a subspecies venerealis specific real-time PCR (ISCfe1) failed due to sequence variation of the target insertion sequence and prevalence in other Campylobacter species. None of the published PCR assays was able to identify C. fetus strains correctly at subspecies level. Molecular analysis by AFLP or MLST is still recommended to identify C. fetus isolates at subspecies level. © 2013. Published by Elsevier B.V. All rights reserved.

  3. An Optimal Calibration Method for a MEMS Inertial Measurement Unit

    Directory of Open Access Journals (Sweden)

    Bin Fang

    2014-02-01

    Full Text Available An optimal calibration method for a micro-electro-mechanical inertial measurement unit (MIMU is presented in this paper. The accuracy of the MIMU is highly dependent on calibration to remove the deterministic errors of systematic errors, which also contain random errors. The overlapping Allan variance is applied to characterize the types of random error terms in the measurements. The calibration model includes package misalignment error, sensor-to-sensor misalignment error and bias, and a scale factor is built. The new concept of a calibration method, which includes a calibration scheme and a calibration algorithm, is proposed. The calibration scheme is designed by D-optimal and the calibration algorithm is deduced by a Kalman filter. In addition, the thermal calibration is investigated, as the bias and scale factor varied with temperature. The simulations and real tests verify the effectiveness of the proposed calibration method and show that it is better than the traditional method.

  4. CERN Diversity Newsletter - September 2016

    CERN Document Server

    Guinot, Genevieve

    2016-01-01

    Quarterly CERN Diversity Newsletter, informing on recent and ongoing diversity activities, and interesting reads, videos and other links related to diversity. Subscribe here: https://diversity.web.cern.ch/2015/07/subscribe-diversity-newsletter

  5. CERN Diversity Newsletter - November 2015

    CERN Document Server

    Kaltenhauser, Kristin; CERN. Geneva. HR Department

    2015-01-01

    Quarterly CERN Diversity Newsletter, informing on recent and ongoing diversity activities, and interesting reads, videos and other links related to diversity. Subscribe here: https://diversity.web.cern.ch/2015/07/subscribe-diversity-newsletter

  6. CERN Diversity Newsletter - March 2016

    CERN Document Server

    Kaltenhauser, Kristin; CERN. Geneva. HR Department

    2016-01-01

    Quarterly CERN Diversity Newsletter, informing on recent and ongoing diversity activities, and interesting reads, videos and other links related to diversity. Subscribe here: https://diversity.web.cern.ch/2015/07/subscribe-diversity-newsletter

  7. CERN Diversity Newsletter - April 2017

    CERN Document Server

    AUTHOR|(CDS)2069427; Koutava, Ioanna; CERN. Geneva. HR Department

    2017-01-01

    The CERN Diversity Newsletter, informing on recent and ongoing diversity activities, and interesting reads, videos and other links related to diversity. Subscribe here: https://diversity.web.cern.ch/2015/07/subscribe-diversity-newsletter

  8. Comparison of serum and red blood cell folate microbiologic assays for national population surveys.

    Science.gov (United States)

    Pfeiffer, Christine M; Zhang, Mindy; Lacher, David A; Molloy, Anne M; Tamura, Tsunenobu; Yetley, Elizabeth A; Picciano, Mary-Frances; Johnson, Clifford L

    2011-07-01

    Three laboratories participated with their laboratory-specific microbiologic growth assays (MA) in the NHANES 2007-2008 to assess whether the distributions of serum (n = 2645) and RBC folate (n = 2613) for the same one-third sample of participants were comparable among laboratories. Laboratory (L) 2 produced the highest and L1 the lowest serum and RBC folate geometric means (nmol/L) in the NHANES sample (serum: L1, 39.5; L2, 59.2; L3, 47.7; and RBC: L1, 1120; L2, 1380; L3, 1380). Each laboratory produced different reference intervals for the central 95% of the population. Pearson correlation coefficients were highest between L3 and L1 (serum, r = 0.95; RBC, r = 0.92) and lowest between L2 and L1 (serum, r = 0.81; RBC, r = 0.65). Notable procedural differences among the laboratories were the Lactobacillus rhamnosus microorganism (L1 and L3: chloramphenicol resistant, L2: wild type) and the calibrator [L1: [6S]5-methyltetrahydrofolate (5-methylTHF), L2: [6R,S] 5-formyltetrahydrofolate ([6R,S] 5-formylTHF), L3: folic acid (FA)]. Compared with 5-methylTHF as calibrator, the folate results were 22-32% higher with FA as calibrator and 8% higher with 5-formylTHF as calibrator, regardless of the matrix (n = 30 serum, n = 28 RBC). The use of different calibrators explained most of the differences in results between L3 and L1 but not between L2 and L1. The use of the wild-type L. rhamnosus by L2 appeared to be the main reason for the differences in results between L2 and the other 2 laboratories. These findings indicate how assay variations influence MA folate results and how those variations can affect population data. To ensure data comparability, better assay harmonization is needed.

  9. Quantification of biofilm exopolysaccharides using an in situ assay with periodic acid-Schiff reagent.

    Science.gov (United States)

    Randrianjatovo-Gbalou, I; Girbal-Neuhauser, E; Marcato-Romain, C-E

    2016-05-01

    A novel approach to the quantification of extracellular polysaccharides in miniaturized biofilms presenting a wide variety of extracellular matrices was developed. The assay used the periodic acid-Schiff reagent and was first calibrated on dextran and alginate solutions. Then it was implemented on 24-h and 48-h biofilms from three strains known to produce different exopolymeric substances (Pseudomonas aeruginosa, Bacillus licheniformis, Weissella confusa). The assay allowed quantification of the total exopolysaccharides, taking into account possible interferences due to cells or other main expolymers of the matrix (eDNA, proteins). Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Comparison calibration of piezoresistive microphones for acoustic power measurements

    OpenAIRE

    Stockermans, Ron J.

    1992-01-01

    Approved for public release; distribution is unlimited A calibration of two Endevco piezoresistive microphones was carried out under static and dynamics pressures. The dynamic pressure calibrations were done by comparison with a B&K condenser microphone. The calibration was carried out in a small closed volume in air and helium. In helium, the codes volume was pressurized to atmospheric pressure and then 10 Atm. The dynamic calibration would determine the "flatness" of the calibration ...

  11. A Review of Sensor Calibration Monitoring for Calibration Interval Extension in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Coble, Jamie B.; Meyer, Ryan M.; Ramuhalli, Pradeep; Bond, Leonard J.; Hashemian, Hash; Shumaker, Brent; Cummins, Dara

    2012-08-31

    Currently in the United States, periodic sensor recalibration is required for all safety-related sensors, typically occurring at every refueling outage, and it has emerged as a critical path item for shortening outage duration in some plants. Online monitoring can be employed to identify those sensors that require calibration, allowing for calibration of only those sensors that need it. International application of calibration monitoring, such as at the Sizewell B plant in United Kingdom, has shown that sensors may operate for eight years, or longer, within calibration tolerances. This issue is expected to also be important as the United States looks to the next generation of reactor designs (such as small modular reactors and advanced concepts), given the anticipated longer refueling cycles, proposed advanced sensors, and digital instrumentation and control systems. The U.S. Nuclear Regulatory Commission (NRC) accepted the general concept of online monitoring for sensor calibration monitoring in 2000, but no U.S. plants have been granted the necessary license amendment to apply it. This report presents a state-of-the-art assessment of online calibration monitoring in the nuclear power industry, including sensors, calibration practice, and online monitoring algorithms. This assessment identifies key research needs and gaps that prohibit integration of the NRC-approved online calibration monitoring system in the U.S. nuclear industry. Several needs are identified, including the quantification of uncertainty in online calibration assessment; accurate determination of calibration acceptance criteria and quantification of the effect of acceptance criteria variability on system performance; and assessment of the feasibility of using virtual sensor estimates to replace identified faulty sensors in order to extend operation to the next convenient maintenance opportunity. Understanding the degradation of sensors and the impact of this degradation on signals is key to

  12. Calibration Monitoring for Sensor Calibration Interval Extension: Gaps in the Current Science Base

    Energy Technology Data Exchange (ETDEWEB)

    Coble, Jamie B.; Ramuhalli, Pradeep; Meyer, Ryan M.; Hashemian, Hash; Shumaker, Brent; Cummins, Dara

    2012-10-09

    Currently in the United States, periodic sensor recalibration is required for all safety-related sensors, typically occurring at every refueling outage, and it has emerged as a critical path item for shortening outage duration in some plants. International application of calibration monitoring has shown that sensors may operate for longer periods within calibration tolerances. This issue is expected to also be important as the United States looks to the next generation of reactor designs (such as small modular reactors and advanced concepts), given the anticipated longer refueling cycles, proposed advanced sensors, and digital instrumentation and control systems. Online monitoring (OLM) can be employed to identify those sensors that require calibration, allowing for calibration of only those sensors that need it. The U.S. Nuclear Regulatory Commission (NRC) accepted the general concept of OLM for sensor calibration monitoring in 2000, but no U.S. plants have been granted the necessary license amendment to apply it. This paper summarizes a recent state-of-the-art assessment of online calibration monitoring in the nuclear power industry, including sensors, calibration practice, and OLM algorithms. This assessment identifies key research needs and gaps that prohibit integration of the NRC-approved online calibration monitoring system in the U.S. nuclear industry. Several technical needs were identified, including an understanding of the impacts of sensor degradation on measurements for both conventional and emerging sensors; the quantification of uncertainty in online calibration assessment; determination of calibration acceptance criteria and quantification of the effect of acceptance criteria variability on system performance; and assessment of the feasibility of using virtual sensor estimates to replace identified faulty sensors in order to extend operation to the next convenient maintenance opportunity.

  13. Calibrating damping rates with LEGACY linewidths

    Science.gov (United States)

    Houdek, Günter

    2017-10-01

    Linear damping rates of radial oscillation modes in selected Kepler stars are estimated with the help of a nonadiabatic stability analysis. The convective fluxes are obtained from a nonlocal, time-dependent convection model. The mixing-length parameter is calibrated to the surface-convection-zone depth of a stellar model obtained from fitting adiabatic frequencies to the LEGACY* observations, and two of the three nonlocal convection parameters are calibrated to the corresponding LEGACY* linewidth measurements. The atmospheric structure in the 1D stability analysis adopts a temperature-optical-depth relation derived from 3D hydrodynamical simulations. Results from 3D simulations are also used to calibrate the turbulent pressure and to guide the functional form of the depth-dependence of the anisotropy of the turbulent velocity field in the 1D stability computations.

  14. ATLAS Tile calorimeter calibration and monitoring systems

    CERN Document Server

    Cortes-Gonzalez, Arely; The ATLAS collaboration

    2017-01-01

    The ATLAS Tile Calorimeter is the central section of the hadronic calorimeter of the ATLAS experiment and provides important information for reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibres to photomultiplier tubes, located in the outer part of the calorimeter. The readout is segmented into about 5000 cells (longitudinally and transversally), each of them being read out by two photomultiplier in parallel. To calibrate and monitor the stability and performance of each part of the readout chain during the data taking, a set of calibration systems is used. The calibration system comprises Cesium radioactive sources, laser, charge injection elements and an integrator based readout system. Combined information from all systems allows to monitor and equalise the calorimeter r...

  15. ATLAS Tile calorimeter calibration and monitoring systems

    CERN Document Server

    Boumediene, Djamel Eddine; The ATLAS collaboration

    2017-01-01

    The ATLAS Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment and provides important information for reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibres to photomultiplier tubes (PMTs). PMT signals are then digitized at 40 MHz and stored on detector and are only transferred off detector once the first level trigger acceptance has been confirmed. The readout is segmented into about 5000 cells (longitudinally and transversally), each of them being read out by two PMTs in parallel. To calibrate and monitor the stability and performance of each part of the readout chain, a set of calibration systems is used. The TileCal calibration system comprises Cesium radioactive sources, laser, charge injection elements and an integrator b...

  16. Laser Calibration of the ATLAS Tile Calorimeter

    CERN Document Server

    Di Gregorio, Giulia; The ATLAS collaboration

    2017-01-01

    High performance stability of the ATLAS Tile Calorimeter is achieved with a set of calibration procedures. One step of the calibration procedure is based on measurements of the response stability to laser excitation of the PMTs that are used to readout the calorimeter cells. A facility to study in lab the PMT stability response is operating in the PISA-INFN laboratories since 2015. Goals of the tests in lab are to study the time evolution of the PMT response to reproduce and to understand the origin of the response drifts seen with the PMT mounted on the Tile calorimeter in its normal operating during LHC run I and run II. A new statistical approach was developed to measure drift of the absolute gain. This approach was applied to both the ATLAS laser calibration data and to data collected in the Pisa local laboratory. The preliminary results from these two studies are shown.

  17. Autonomous calibration of single spin qubit operations

    Science.gov (United States)

    Frank, Florian; Unden, Thomas; Zoller, Jonathan; Said, Ressa S.; Calarco, Tommaso; Montangero, Simone; Naydenov, Boris; Jelezko, Fedor

    2017-12-01

    Fully autonomous precise control of qubits is crucial for quantum information processing, quantum communication, and quantum sensing applications. It requires minimal human intervention on the ability to model, to predict, and to anticipate the quantum dynamics, as well as to precisely control and calibrate single qubit operations. Here, we demonstrate single qubit autonomous calibrations via closed-loop optimisations of electron spin quantum operations in diamond. The operations are examined by quantum state and process tomographic measurements at room temperature, and their performances against systematic errors are iteratively rectified by an optimal pulse engineering algorithm. We achieve an autonomous calibrated fidelity up to 1.00 on a time scale of minutes for a spin population inversion and up to 0.98 on a time scale of hours for a single qubit π/2 -rotation within the experimental error of 2%. These results manifest a full potential for versatile quantum technologies.

  18. ATLAS Tile calorimeter calibration and monitoring systems

    CERN Document Server

    Chomont, Arthur Rene; The ATLAS collaboration

    2016-01-01

    The ATLAS Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment and provides important information for reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibres to photomultiplier tubes (PMTs), located on the outside of the calorimeter. The readout is segmented into about 5000 cells (longitudinally and transversally), each of them being read out by two PMTs in parallel. To calibrate and monitor the stability and performance of each part of the readout chain during the data taking, a set of calibration systems is used. The TileCal calibration system comprises Cesium radioactive sources, laser and charge injection elements and it allows to monitor and equalize the calorimeter response at each stage of the signal production, from scin...

  19. Energy Calibration of Double Chooz Detector

    Science.gov (United States)

    Yang, Guang

    2013-04-01

    Reactor anti-neutrino oscillation experiment Double Chooz was designed to measure the mixing angle theta-13 with unprecedented sensitivity. The Double Chooz detector system consists of a main detector, an outer veto system and several calibration systems. The main detector has a cylindrical structure. It consists of the target vessel, a liquid scintillator loaded with Gd, surrounded by the gamma-catcher, a non-loaded liquid scintillator. A buffer region of non-scintillating liquid surrounds the gamma-catcher and serves to host 390 photomultiplier tubes and to decrease the level of accidental background. The Inner Veto region is outside the buffer, and the Outer Veto system covers all detector components. Far detector is operational and the near detector is under construction. The detector is calibrated with light sources, radioactive point sources, cosmics and natural radioactivity. In this presentation we will describe use of radioactive calibration sources and cross-checks performed with cosmics and natural radioactivity.

  20. The Importance of Calibration in Clinical Psychology.

    Science.gov (United States)

    Lindhiem, Oliver; Petersen, Isaac T; Mentch, Lucas K; Youngstrom, Eric A

    2018-02-01

    Accuracy has several elements, not all of which have received equal attention in the field of clinical psychology. Calibration, the degree to which a probabilistic estimate of an event reflects the true underlying probability of the event, has largely been neglected in the field of clinical psychology in favor of other components of accuracy such as discrimination (e.g., sensitivity, specificity, area under the receiver operating characteristic curve). Although it is frequently overlooked, calibration is a critical component of accuracy with particular relevance for prognostic models and risk-assessment tools. With advances in personalized medicine and the increasing use of probabilistic (0% to 100%) estimates and predictions in mental health research, the need for careful attention to calibration has become increasingly important.

  1. CERN radiation protection (RP) calibration facilities

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi, Fabio

    2016-04-14

    Radiation protection calibration facilities are essential to ensure the correct operation of radiation protection instrumentation. Calibrations are performed in specific radiation fields according to the type of instrument to be calibrated: neutrons, photons, X-rays, beta and alpha particles. Some of the instruments are also tested in mixed radiation fields as often encountered close to high-energy particle accelerators. Moreover, calibration facilities are of great importance to evaluate the performance of prototype detectors; testing and measuring the response of a prototype detector to well-known and -characterized radiation fields contributes to improving and optimizing its design and capabilities. The CERN Radiation Protection group is in charge of performing the regular calibrations of all CERN radiation protection devices; these include operational and passive dosimeters, neutron and photon survey-meters, and fixed radiation detectors to monitor the ambient dose equivalent, H*(10), inside CERN accelerators and at the CERN borders. A new state-of-the-art radiation protection calibration facility was designed, constructed and commissioned following the related ISO recommendations to replace the previous ageing (more than 30 years old) laboratory. In fact, the new laboratory aims also at the official accreditation according to the ISO standards in order to be able to release certified calibrations. Four radiation fields are provided: neutrons, photons and beta sources and an X-ray generator. Its construction did not only involve a pure civil engineering work; many radiation protection studies were performed to provide a facility that could answer the CERN calibration needs and fulfill all related safety requirements. Monte Carlo simulations have been confirmed to be a valuable tool for the optimization of the building design, the radiation protection aspects, e.g. shielding, and, as consequence, the overall cost. After the source and irradiator installation

  2. Generic methodology for calibrating profiling nacelle lidars

    DEFF Research Database (Denmark)

    Borraccino, Antoine; Courtney, Michael; Wagner, Rozenn

    Improving power performance assessment by measuring at different heights has been demonstrated using ground-based profiling LIDARs. More recently, nacelle-mounted lidars studies have shown promising capabilities to assess power performance. Using nacelle lidars avoids the erection of expensive...... meteorology masts, especially offshore. A new generation of commercially developed profiling nacelle lidars has sophisticated measurement capabilities. As for any other measuring system, lidars measurements have uncertainties. Their estimation is the ultimate goal of a calibration. Field calibration...... procedures have been developed for non-profiling nacelle lidars. However, their specificity to one type of lidar or another highlights the need for developing generic calibration procedures. Such procedures should be applicable to any type of existing and upcoming lidar technology. Profiling nacelle lidars...

  3. Calibration of the TFTR lost alpha diagnostic

    Science.gov (United States)

    Boivin, R. L.; Lin, Z.; Roquemore, A. L.; Zweben, S. J.

    1992-10-01

    We present various aspects of the calibration of the TFTR lost alpha diagnostic. The diagnostic consists of four detectors, forming a poloidal array at the bottom of TFTR inside the vacuum vessel. The detector is composed of a ZnS(Ag) scintillator and a pair of collimating apertures which permit pitch angle, energy, and time resolution of the escaping flux of high-energy ions (MeV range). The first goal of this study was to establish the absolute calibration of the diagnostic for different particle types and energies. This enables us to compare for the first time, measured losses with loss calculations based on a first-orbit model. However, the factor of 2 uncertainty in the final calibration is still too large for full, quantitative comparisons of the data with the theory based on absolute flux measurements alone. We also present some of the aspects related to the detector's resolution capabilities, its temperature dependence, and its time response.

  4. Comet Assay in Cancer Chemoprevention.

    Science.gov (United States)

    Santoro, Raffaela; Ferraiuolo, Maria; Morgano, Gian Paolo; Muti, Paola; Strano, Sabrina

    2016-01-01

    The comet assay can be useful in monitoring DNA damage in single cells caused by exposure to genotoxic agents, such as those causing air, water, and soil pollution (e.g., pesticides, dioxins, electromagnetic fields) and chemo- and radiotherapy in cancer patients, or in the assessment of genoprotective effects of chemopreventive molecules. Therefore, it has particular importance in the fields of pharmacology and toxicology, and in both environmental and human biomonitoring. It allows the detection of single strand breaks as well as double-strand breaks and can be used in both normal and cancer cells. Here we describe the alkali method for comet assay, which allows to detect both single- and double-strand DNA breaks.

  5. Improving calibration accuracy in gel dosimetry

    Science.gov (United States)

    Oldham, M.; McJury, M.; Baustert, I. B.; Webb, S.; Leach, M. O.

    1998-10-01

    A new method of calibrating gel dosimeters (applicable to both Fricke and polyacrylamide gels) is presented which has intrinsically higher accuracy than current methods, and requires less gel. Two test-tubes of gel (inner diameter 2.5 cm, length 20 cm) are irradiated separately with a field end-on in a water bath, such that the characteristic depth-dose curve is recorded in the gel. The calibration is then determined by fitting the depth-dose measured in water, against the measured change in relaxivity with depth in the gel. Increased accuracy is achieved in this simple depth-dose geometry by averaging the relaxivity at each depth. A large number of calibration data points, each with relatively high accuracy, are obtained. Calibration data over the full range of dose (1.6-10 Gy) is obtained by irradiating one test-tube to 10 Gy at dose maximum , and the other to 4.5 Gy at . The new calibration method is compared with a `standard method' where five identical test-tubes of gel were irradiated to different known doses between 2 and 10 Gy. The percentage uncertainties in the slope and intercept of the calibration fit are found to be lower with the new method by a factor of about 4 and 10 respectively, when compared with the standard method and with published values. The gel was found to respond linearly within the error bars up to doses of 7 Gy, with a slope of and an intercept of Gy. For higher doses, nonlinear behaviour was observed.

  6. Protein binding assay for hyaluronate

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, B.E.; Underhill, C.B.

    1986-11-01

    A relatively quick and simple assay for hyaluronate was developed using the specific binding protein, hyaluronectin. The hyaluronectin was obtained by homogenizing the brains of Sprague-Dawley rats, and then centrifuging the homogenate. The resulting supernatant was used as a source of crude hyaluronectin. In the binding assay, the hyaluronectin was mixed with (/sup 3/H)hyaluronate, followed by an equal volume of saturated (NH/sub 4/)/sub 2/SO/sub 4/, which precipitated the hyaluronectin and any (/sup 3/H)hyaluronate associated with it, but left free (/sup 3/H)hyaluronate in solution. The mixture was then centrifuged, and the amount of bound (/sup 3/H)hyaluronate in the precipitate was determined. Using this assay, the authors found that hyaluronectin specifically bound hyaluronate, since other glycosaminoglycans failed to compete for the binding protein. In addition, the interaction between hyaluronectin and hyaluronate was of relatively high affinity, and the size of the hyaluronate did not appear to substantially alter the amount of binding. To determine the amount of hyaluronate in an unknown sample, they used a competition assay in which the binding of a set amount of (/sup 3/H)hyaluronate was blocked by the addition of unlabeled hyaluronate. By comparing the degree of competition of the unknown samples with that of known amounts of hyaluronate, it was possible to determine the amount of hyaluronate in the unknowns. They have found that this method is sensitive to 1 ..mu..g or less of hyaluronate, and is unaffected by the presence of proteins.

  7. Utilization of microparticles in next-generation assays for microflow cytometers

    OpenAIRE

    Kim, Jason S.; Ligler, Frances S.

    2010-01-01

    Micron-sized particles have primarily been used in microfabricated flow cytometers for calibration purposes and proof-of-concept experiments. With increasing frequency, microparticles are serving as a platform for assays measured in these small analytical devices. Light scattering has been used to measure the agglomeration of antibody-coated particles in the presence of an antigen. Impedance detection is another technology being integrated into microflow cytometers for microparticle-based ass...

  8. On performance experience and measurements with Ningyo Waste Assay System (NWAS)

    OpenAIRE

    在間 直樹; 中島 伸一; 金田 弘司; 門 一実

    2011-01-01

    The uranium mass assay systems for 200-litter wastes drums applied neutron and gamma measurements by NDA method had been developed. The measurement systems and trial data are described in this preliminary report. The systems are composed of the 16 pieces of helium-3 proportional counters for neutron detection and a large sized NaI(Tl) scintillation detector for gamma ray detection. The extensive testing trials using the calibrated uranium sources with different enrichment and some kinds of ma...

  9. Uranium daughter growth must not be neglected when adjusting plutonium materials for assay and isotopic contents

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, S.F.; Spall, W.D.; Abernathey, R.M.; Rein, J.E.

    1976-11-01

    Relationships are provided to compute the decreasing plutonium content and changing isotopic distribution of plutonium materials for the radioactive decay of /sup 238/Pu, /sup 239/Pu, /sup 240/Pu and /sup 242/Pu to long-lived uranium daughters and of /sup 241/Pu to /sup 241/Am. This computation is important to the use of plutonium reference materials to calibrate destructive and nondestructive methods for assay and isotopic measurements, as well as to accountability inventory calculations.

  10. Probability based calibration of pressure coefficients

    DEFF Research Database (Denmark)

    Hansen, Svend Ole; Pedersen, Marie Louise; Sørensen, John Dalsgaard

    2015-01-01

    not depend on the type of variable action. A probability based calibration of pressure coefficients have been carried out using pressure measurements on the standard CAARC building modelled on scale of 1:383. The extreme pressures measured on the CAARC building model in the wind tunnel have been fitted...... to Gumbel distributions, and these fits are found to represent the data measured with good accuracy. The pressure distributions found have been used in a calibration of partial factors, which should achieve a certain theoretical target reliability index. For a target annual reliability index of 4...

  11. Planck 2013 results. V. LFI calibration

    Science.gov (United States)

    Planck Collaboration; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cappellini, B.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chen, X.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Colombi, S.; Colombo, L. P. L.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Gaier, T. C.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Kangaslahti, P.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leach, S.; Leahy, J. P.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Paci, F.; Pagano, L.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, D.; Peel, M.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Ricciardi, S.; Riller, T.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    We discuss the methods employed to photometrically calibrate the data acquired by the Low Frequency Instrument on Planck. Our calibration is based on a combination of the orbital dipole plus the solar dipole, caused respectively by the motion of the Planck spacecraft with respect to the Sun and by motion of the solar system with respect to the cosmic microwave background (CMB) rest frame. The latter provides a signal of a few mK with the same spectrum as the CMB anisotropies and is visible throughout the mission. In this data releasewe rely on the characterization of the solar dipole as measured by WMAP. We also present preliminary results (at 44 GHz only) on the study of the Orbital Dipole, which agree with the WMAP value of the solar system speed within our uncertainties. We compute the calibration constant for each radiometer roughly once per hour, in order to keep track of changes in the detectors' gain. Since non-idealities in the optical response of the beams proved to be important, we implemented a fast convolution algorithm which considers the full beam response in estimating the signal generated by the dipole. Moreover, in order to further reduce the impact of residual systematics due to sidelobes, we estimated time variations in the calibration constant of the 30 GHz radiometers (the ones with the largest sidelobes) using the signal of an internal reference load at 4 K instead of the CMB dipole. We have estimated the accuracy of the LFI calibration following two strategies: (1) we have run a set of simulations to assess the impact of statistical errors and systematic effects in the instrument and in the calibration procedure; and (2) we have performed a number of internal consistency checks on the data and on the brightness temperature of Jupiter. Errors in the calibration of this Planck/LFI data release are expected to be about 0.6% at 44 and 70 GHz, and 0.8% at 30 GHz. Both these preliminary results at low and high ℓ are consistent with WMAP results

  12. Fabrication and calibration of search coils

    CERN Document Server

    Buzio, M

    2010-01-01

    In this paper the techniques available to make and calibrate magnetic search coils are reviewed, with emphasis on harmonic coil systems as the commonly-used optimal choice for integral measurements of accelerator magnets in terms of measuring range, accuracy, and cost. The topics treated, drawing extensively on half a century of experience at CERN, include mechanical and electrical design criteria, practical fabrication techniques, metrological considerations, and various calibration methods for coil parameters such as surface area, rotation radius, tilt angle etc. in both static or time-varying magnetic fields.

  13. A simple micro-extraction plate assay for automated LC-MS/MS analysis of human serum 25-hydroxyvitamin D levels.

    Science.gov (United States)

    Geib, Timon; Meier, Florian; Schorr, Pascal; Lammert, Frank; Stokes, Caroline S; Volmer, Dietrich A

    2015-01-01

    This short application note describes a simple and automated assay for determination of 25-hydroxyvitamin D (25(OH)D) levels in very small volumes of human serum. It utilizes commercial 96-well micro-extraction plates with commercial 25(OH)D isotope calibration and quality control kits. Separation was achieved using a pentafluorophenyl liquid chromatography column followed by multiple reaction monitoring-based quantification on an electrospray triple quadrupole mass spectrometer. Emphasis was placed on providing a simple assay that can be rapidly established in non-specialized laboratories within days, without the need for laborious and time consuming sample preparation steps, advanced calibration or data acquisition routines. The analytical figures of merit obtained from this assay compared well to established assays. To demonstrate the applicability, the assay was applied to analysis of serum samples from patients with chronic liver diseases and compared to results from a routine clinical immunoassay. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Enzyme-linked immunosorbent assay characterization of Basal variation and heritability of systemic microfibrillar-associated protein 4

    DEFF Research Database (Denmark)

    Sækmose, Susanne Gjørup; Schlosser, Anders; Holst, René

    2013-01-01

    in systemic MFAP4 (sMFAP4) has the potential to reflect diverse diseases with increased ECM turnover. Here, we aimed to validate an enzyme-linked immunosorbent assay (ELISA) for the measurement of sMFAP4 with an emphasis on the robustness of the assay. Moreover, we aimed to determine confounders influencing...

  15. Managing Workplace Diversity

    Directory of Open Access Journals (Sweden)

    Harold Andrew Patrick

    2012-04-01

    Full Text Available Diversity management is a process intended to create and maintain a positive work environment where the similarities and differences of individuals are valued. The literature on diversity management has mostly emphasized on organization culture; its impact on diversity openness; human resource management practices; institutional environments and organizational contexts to diversity-related pressures, expectations, requirements, and incentives; perceived practices and organizational outcomes related to managing employee diversity; and several other issues. The current study examines the potential barriers to workplace diversity and suggests strategies to enhance workplace diversity and inclusiveness. It is based on a survey of 300 IT employees. The study concludes that successfully managing diversity can lead to more committed, better satisfied, better performing employees and potentially better financial performance for an organization.

  16. International diversity management

    DEFF Research Database (Denmark)

    Lauring, Jakob

    2013-01-01

    While the concern with demographic diversity in organizations has increased during recent years, international diversity management still remains an understudied area. This is unfortunate since the transfer of diversity management practices within multinational corporations faces particular...... challenges in balancing between global integration and local responsiveness. The aim of this paper is to illustrate some of the central problems that multinational corporations need to deal with when transferring diversity management practices from headquarters to local subsidiaries. This is illustrated...

  17. The duplicity of diversity

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2015-01-01

    value; (2) diverting diversity providing pleasure and amusement; and (3) distracting diversity directing attention from something of greater importance. I argue that the concept of diversity can be a fruitful focus in ethnographic research, if its inherent multiplex and duplicitous character...... is recognized and actively employed. This is shown through an analysis of the ways in which immigrants from the English-speaking Caribbean to Denmark have been perceived and received as foreigners since the 1960s as representing different kinds of diversity....

  18. CALIBRATION PROCEDURES ON OBLIQUE CAMERA SETUPS

    Directory of Open Access Journals (Sweden)

    G. Kemper

    2016-06-01

    Full Text Available Beside the creation of virtual animated 3D City models, analysis for homeland security and city planning, the accurately determination of geometric features out of oblique imagery is an important task today. Due to the huge number of single images the reduction of control points force to make use of direct referencing devices. This causes a precise camera-calibration and additional adjustment procedures. This paper aims to show the workflow of the various calibration steps and will present examples of the calibration flight with the final 3D City model. In difference to most other software, the oblique cameras are used not as co-registered sensors in relation to the nadir one, all camera images enter the AT process as single pre-oriented data. This enables a better post calibration in order to detect variations in the single camera calibration and other mechanical effects. The shown sensor (Oblique Imager is based o 5 Phase One cameras were the nadir one has 80 MPIX equipped with a 50 mm lens while the oblique ones capture images with 50 MPix using 80 mm lenses. The cameras are mounted robust inside a housing to protect this against physical and thermal deformations. The sensor head hosts also an IMU which is connected to a POS AV GNSS Receiver. The sensor is stabilized by a gyro-mount which creates floating Antenna –IMU lever arms. They had to be registered together with the Raw GNSS-IMU Data. The camera calibration procedure was performed based on a special calibration flight with 351 shoots of all 5 cameras and registered the GPS/IMU data. This specific mission was designed in two different altitudes with additional cross lines on each flying heights. The five images from each exposure positions have no overlaps but in the block there are many overlaps resulting in up to 200 measurements per points. On each photo there were in average 110 well distributed measured points which is a satisfying number for the camera calibration. In a first

  19. Calibration Procedures on Oblique Camera Setups

    Science.gov (United States)

    Kemper, G.; Melykuti, B.; Yu, C.

    2016-06-01

    Beside the creation of virtual animated 3D City models, analysis for homeland security and city planning, the accurately determination of geometric features out of oblique imagery is an important task today. Due to the huge number of single images the reduction of control points force to make use of direct referencing devices. This causes a precise camera-calibration and additional adjustment procedures. This paper aims to show the workflow of the various calibration steps and will present examples of the calibration flight with the final 3D City model. In difference to most other software, the oblique cameras are used not as co-registered sensors in relation to the nadir one, all camera images enter the AT process as single pre-oriented data. This enables a better post calibration in order to detect variations in the single camera calibration and other mechanical effects. The shown sensor (Oblique Imager) is based o 5 Phase One cameras were the nadir one has 80 MPIX equipped with a 50 mm lens while the oblique ones capture images with 50 MPix using 80 mm lenses. The cameras are mounted robust inside a housing to protect this against physical and thermal deformations. The sensor head hosts also an IMU which is connected to a POS AV GNSS Receiver. The sensor is stabilized by a gyro-mount which creates floating Antenna -IMU lever arms. They had to be registered together with the Raw GNSS-IMU Data. The camera calibration procedure was performed based on a special calibration flight with 351 shoots of all 5 cameras and registered the GPS/IMU data. This specific mission was designed in two different altitudes with additional cross lines on each flying heights. The five images from each exposure positions have no overlaps but in the block there are many overlaps resulting in up to 200 measurements per points. On each photo there were in average 110 well distributed measured points which is a satisfying number for the camera calibration. In a first step with the help of

  20. Standard test method for nondestructive assay of radioactive material by tomographic gamma scanning

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method describes the nondestructive assay (NDA) of gamma ray emitting radionuclides inside containers using tomographic gamma scanning (TGS). High resolution gamma ray spectroscopy is used to detect and quantify the radionuclides of interest. The attenuation of an external gamma ray transmission source is used to correct the measurement of the emission gamma rays from radionuclides to arrive at a quantitative determination of the radionuclides present in the item. 1.2 The TGS technique covered by the test method may be used to assay scrap or waste material in cans or drums in the 1 to 500 litre volume range. Other items may be assayed as well. 1.3 The test method will cover two implementations of the TGS procedure: (1) Isotope Specific Calibration that uses standards of known radionuclide masses (or activities) to determine system response in a mass (or activity) versus corrected count rate calibration, that applies to only those specific radionuclides for which it is calibrated, and (2) Respo...

  1. Leadership and Diversity

    Science.gov (United States)

    Coleman, Marianne

    2012-01-01

    As part of the special edition recognizing the 40th anniversary of "Educational Management Administration & Leadership" this article reviews the coverage of leadership and diversity issues in the journal. The majority of articles concerning diversity have focused on gender, with attention turning to the wider concept of diversity since the year…

  2. The State of Diversity.

    Science.gov (United States)

    Josey, E. J.

    1994-01-01

    Examines what is being done to implement cultural diversity in libraries. Topics addressed include affirmative action; defining cultural diversity, including the significance of ethnicity, race, and race relations in the workplace; problems in implementing cultural diversity; and examples of successful implementation programs. (Contains three…

  3. Thinking about Diversity.

    Science.gov (United States)

    Anderson, James A.

    1993-01-01

    Before companies attempt to increase the diversity in their management ranks, it is necessary for them to learn to manage diversity. Managers should have a plan; focus on individual learning, human-relations, motivational, and communication styles; examine organizational culture; and offer diversity training. (JOW)

  4. Diversity does not travel!

    DEFF Research Database (Denmark)

    Lund, Rebecca; Meriläinen, Susan; Tienari, Janne

    2013-01-01

    In this chapter we offer insights into the social construction of diversity in Finnish organizations and society. In Finnish organizations, gender is highlighted while other markers of diversity are blotted out. 'Non-Finns' become subject to cultural assimilation. The US-based concept of Diversity...

  5. An image analysis toolbox for high-throughput C. elegans assays.

    Science.gov (United States)

    Wählby, Carolina; Kamentsky, Lee; Liu, Zihan H; Riklin-Raviv, Tammy; Conery, Annie L; O'Rourke, Eyleen J; Sokolnicki, Katherine L; Visvikis, Orane; Ljosa, Vebjorn; Irazoqui, Javier E; Golland, Polina; Ruvkun, Gary; Ausubel, Frederick M; Carpenter, Anne E

    2012-04-22

    We present a toolbox for high-throughput screening of image-based Caenorhabditis elegans phenotypes. The image analysis algorithms measure morphological phenotypes in individual worms and are effective for a variety of assays and imaging systems. This WormToolbox is available through the open-source CellProfiler project and enables objective scoring of whole-worm high-throughput image-based assays of C. elegans for the study of diverse biological pathways that are relevant to human disease.

  6. New approach in multipurpose optical diagnostics: fluorescence based assay for simultaneous determination of physicochemical parameters

    OpenAIRE

    Moczko, Ewa

    2009-01-01

    The development of sensors assays for comprehensive characterisation of biological samples and effective minimal-invasive diagnostics is highly prioritised. Last decade this research area has been actively developing due to possibility of simultaneous, real- time, in vivo detection and monitoring of diverse physicochemical parameters and analytes. The new approach which has been introduced in this thesis was to develop and examine an optical diagnostic assay consisting of a ...

  7. DNA-DNA hybridization assay for detection of Salmonella spp. in foods.

    OpenAIRE

    Fitts, R; Diamond, M.; Hamilton, C; Neri, M.

    1983-01-01

    We have developed a DNA-DNA hybridization test for the presence of Salmonella spp. in foods. This test requires an initial pre-enrichment of food samples in nutrient broth but does not require selective enrichment. Samples of food cultures are collected on membrane filters and assayed by molecular hybridization to labeled probes. The probes consist of DNA sequences which are unique to the genus Salmonella and are widely distributed in the genus. A diverse panel of foods was assayed successful...

  8. On the prospects of cross-calibrating the Cherenkov Telescope Array with an airborne calibration platform

    Science.gov (United States)

    Brown, Anthony M.

    2018-01-01

    Recent advances in unmanned aerial vehicle (UAV) technology have made UAVs an attractive possibility as an airborne calibration platform for astronomical facilities. This is especially true for arrays of telescopes spread over a large area such as the Cherenkov Telescope Array (CTA). In this paper, the feasibility of using UAVs to calibrate CTA is investigated. Assuming a UAV at 1km altitude above CTA, operating on astronomically clear nights with stratified, low atmospheric dust content, appropriate thermal protection for the calibration light source and an onboard photodiode to monitor its absolute light intensity, inter-calibration of CTA's telescopes of the same size class is found to be achievable with a 6 - 8 % uncertainty. For cross-calibration of different telescope size classes, a systematic uncertainty of 8 - 10 % is found to be achievable. Importantly, equipping the UAV with a multi-wavelength calibration light source affords us the ability to monitor the wavelength-dependent degradation of CTA telescopes' optical system, allowing us to not only maintain this 6 - 10 % uncertainty after the first few years of telescope deployment, but also to accurately account for the effect of multi-wavelength degradation on the cross-calibration of CTA by other techniques, namely with images of air showers and local muons. A UAV-based system thus provides CTA with several independent and complementary methods of cross-calibrating the optical throughput of individual telescopes. Furthermore, housing environmental sensors on the UAV system allows us to not only minimise the systematic uncertainty associated with the atmospheric transmission of the calibration signal, it also allows us to map the dust content above CTA as well as monitor the temperature, humidity and pressure profiles of the first kilometre of atmosphere above CTA with each UAV flight.

  9. SCIAMACHY Level 1 data: calibration concept and in-flight calibration

    Directory of Open Access Journals (Sweden)

    G. Lichtenberg

    2006-01-01

    Full Text Available The calibration of SCIAMACHY was thoroughly checked since the instrument was launched on-board ENVISAT in February 2002. While SCIAMACHY's functional performance is excellent since launch, a number of technical difficulties have appeared, that required adjustments to the calibration. The problems can be separated into three types: (1 Those caused by the instrument and/or platform environment. Among these are the high water content in the satellite structure and/or MLI layer. This results in the deposition of ice on the detectors in channels 7 and 8 which seriously affects the retrievals in the IR, mostly because of the continuous change of the slit function caused by scattering of the light through the ice layer. Additionally a light leak in channel 7 severely hampers any retrieval from this channel. (2 Problems due to errors in the on-ground calibration and/or data processing affecting for example the radiometric calibration. A new approach based on a mixture of on-ground and in-flight data is shortly described here. (3 Problems caused by principal limitations of the calibration concept, e.g. the possible appearance of spectral structures after the polarisation correction due to unavoidable errors in the determination of atmospheric polarisation. In this paper we give a complete overview of the calibration and problems that still have to be solved. We will also give an indication of the effect of calibration problems on retrievals where possible. Since the operational processing chain is currently being updated and no newly processed data are available at this point in time, for some calibration issues only a rough estimate of the effect on Level 2 products can be given. However, it is the intention of this paper to serve as a future reference for detailed studies into specific calibration issues.

  10. Next Generation Safeguards Initiative research to determine the Pu mass in spent fuel assemblies: Purpose, approach, constraints, implementation, and calibration

    Science.gov (United States)

    Tobin, S. J.; Menlove, H. O.; Swinhoe, M. T.; Schear, M. A.

    2011-10-01

    The Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy has funded a multi-lab/multi-university collaboration to quantify the plutonium mass in spent nuclear fuel assemblies and to detect the diversion of pins from them. The goal of this research effort is to quantify the capability of various non-destructive assay (NDA) technologies as well as to train a future generation of safeguards practitioners. This research is "technology driven" in the sense that we will quantify the capabilities of a wide range of safeguards technologies of interest to regulators and policy makers; a key benefit to this approach is that the techniques are being tested in a unified manner. When the results of the Monte Carlo modeling are evaluated and integrated, practical constraints are part of defining the potential context in which a given technology might be applied. This paper organizes the commercial spent fuel safeguard needs into four facility types in order to identify any constraints on the NDA system design. These four facility types are the following: future reprocessing plants, current reprocessing plants, once-through spent fuel repositories, and any other sites that store individual spent fuel assemblies (reactor sites are the most common facility type in this category). Dry storage is not of interest since individual assemblies are not accessible. This paper will overview the purpose and approach of the NGSI spent fuel effort and describe the constraints inherent in commercial fuel facilities. It will conclude by discussing implementation and calibration of measurement systems. This report will also provide some motivation for considering a couple of other safeguards concepts (base measurement and fingerprinting) that might meet the safeguards need but not require the determination of plutonium mass.

  11. Calibration of soil heat flux sensors.

    NARCIS (Netherlands)

    Loon, van W.K.P.; Bastings, H.M.H.; Moors, E.J.

    1998-01-01

    Soil heat flux is difficult to measure accurately and soil heat flux plates are difficult to calibrate. In this research the reference heat flux was calculated from the temperature gradient and independent thermal conductivity measurements. Reference conductivities, as measured by the non-steady

  12. The calibration of traffic-conflict techniques.

    NARCIS (Netherlands)

    Oppe, S.

    1983-01-01

    A calibration study has been planned in order to find similarities and dissimilarities between the scoring systems of observers (scales, dimensions) and a comprehension of these with regard to the more objective characteristics of the conflict situations. This, in order to compare results. The data

  13. Jet energy calibration at the LHC

    CERN Document Server

    INSPIRE-00053381

    2015-01-01

    Jets are one of the most prominent physics signatures of high energy proton proton (p-p) collisions at the Large Hadron Collider (LHC). They are key physics objects for precision measurements and searches for new phenomena. This review provides an overview of the reconstruction and calibration of jets at the LHC during its first Run. ATLAS and CMS developed different approaches for the reconstruction of jets, but use similar methods for the energy calibration. ATLAS reconstructs jets utilizing input signals from their calorimeters and use charged particle tracks to refine their energy measurement and suppress the effects of multiple p-p interactions (pileup). CMS, instead, combines calorimeter and tracking information to build jets from particle flow objects. Jets are calibrated using Monte Carlo (MC) simulations and a residual in situ calibration derived from collision data is applied to correct for the differences in jet response between data and Monte Carlo. Large samples of dijet, Z+jets, and photon+jet e...

  14. The Calibration Home Base for Imaging Spectrometers

    Directory of Open Access Journals (Sweden)

    Johannes Felix Simon Brachmann

    2016-08-01

    Full Text Available The Calibration Home Base (CHB is an optical laboratory designed for the calibration of imaging spectrometers for the VNIR/SWIR wavelength range. Radiometric, spectral and geometric calibration as well as the characterization of sensor signal dependency on polarization are realized in a precise and highly automated fashion. This allows to carry out a wide range of time consuming measurements in an ecient way. The implementation of ISO 9001 standards in all procedures ensures a traceable quality of results. Spectral measurements in the wavelength range 380–1000 nm are performed to a wavelength uncertainty of +- 0.1 nm, while an uncertainty of +-0.2 nm is reached in the wavelength range 1000 – 2500 nm. Geometric measurements are performed at increments of 1.7 µrad across track and 7.6 µrad along track. Radiometric measurements reach an absolute uncertainty of +-3% (k=1. Sensor artifacts, such as caused by stray light will be characterizable and correctable in the near future. For now, the CHB is suitable for the characterization of pushbroom sensors, spectrometers and cameras. However, it is planned to extend the CHBs capabilities in the near future such that snapshot hyperspectral imagers can be characterized as well. The calibration services of the CHB are open to third party customers from research institutes as well as industry.

  15. Calibration Procedure for 3D Turning Dynamometer

    DEFF Research Database (Denmark)

    Axinte, Dragos Aurelian; Belluci, Walter

    1999-01-01

    The aim of the static calibration of the dynamometer is to obtain the matrix for evaluating cutting forces through the output voltage of the piezoelectric cells and charge amplifiers. In the same time, it is worth to evaluate the linearity of the dependencies between applied forces and output...

  16. Code Calibration as a Decision Problem

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Kroon, I. B.; Faber, Michael Havbro

    1993-01-01

    Calibration of partial coefficients for a class of structures where no code exists is considered. The partial coefficients are determined such that the difference between the reliability for the different structures in the class considered and a target reliability level is minimized. Code calibra...

  17. RADCAL Operations Manual Radiation Calibration Laboratory Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Bogard, J.S.

    1998-12-01

    The Life Sciences Division (LSD) of Oak Ridge National Laboratory (ORNL) has a long record of radiation dosimetry research, primarily using the Health Physics Research Reactor (HPRR) and the Radiation Calibration Laboratory (RADCAL) in its Dosimetry Applications Research (DOSAR) Program. These facilities have been used by a broad segment of the research community to perform a variety of experiments in areas including, but not limited to, radiobiology, radiation dosimeter and instrumentation development and calibration, and the testing of materials in a variety of radiation environments. Operations of the HPRR were terminated in 1987 and the reactor was moved to storage at the Oak Ridge Y-12 Plant; however, RADCAL will continue to be operated in accordance with the guidelines of the National Institute of Standards and Technology (NIST) Secondary Calibration Laboratory program and will meet all requirements for testing dosimeters under the National Voluntary Laboratory Accreditation Program (NVLAP). This manual is to serve as the primary instruction and operation manual for the Oak Ridge National Laboratory's RADCAL facility. Its purpose is to (1) provide operating protocols for the RADCAL facility, (2) outline the organizational structure, (3) define the Quality Assurance Action Plan, and (4) describe all the procedures, operations, and responsibilities for the safe and proper operation of all routine aspects of the calibration facility.

  18. Developments in radiocarbon calibration for archaeology

    NARCIS (Netherlands)

    Ramsey, Christopher Bronk; Buck, Caitlin E.; Manning, Sturt W.; Reimer, Paula; van der Plicht, Hans

    2006-01-01

    This update on radiocarbon calibration results from the 19th International Radiocarbon Conference at Oxford in April 2006, and is essential reading for all archaeologists. The way radiocarbon dates and absolute dates relate to each other differs in three periods: back to 12400 cal BR radiocarbon

  19. CALIBRATION ET VALIDATION DU MODULE PHOSPHORE DU ...

    African Journals Online (AJOL)

    RECOMMANDATIONS SPECIFIQUES D'ENGRAIS: CALIBRATION ET VALIDATION DU MODULE PHOSPHORE DU MODELE NuMaSS. M. D. Doumbia, A. Sidibé, A. Bagayoko, M. A. Diarra, A. Bationo, R. A. Kablan, R. S. Yost, L. R. Hossner, F. M. Hons ...

  20. Calibration of Cryogenic Thermometers for the LHC

    CERN Document Server

    Balle, Ch; Vauthier, N; Thermeau, JP

    2008-01-01

    6000 cryogenic temperature sensors of resistive type covering the range from room temperature down to 1.6 K are installed on the LHC machine. In order to meet the stringent requirements on temperature control of the superconducting magnets, each single sensor needs to be calibrated individually. In the framework of a special contribution, IPN (Institut de Physique Nucléaire) in Orsay, France built and operated a calibration facility with a throughput of 80 thermometers per week. After reception from the manufacturer, the thermometer is first assembled onto a support specific to the measurement environment, and then thermally cycled ten times and calibrated at least once from 1.6 to 300 K. The procedure for each of these interventions includes various measurements and the acquired data is recorded in an ORACLE®-database. Furthermore random calibrations on some samples are executed at CERN to crosscheck the coherence between the approximation data obtained by both IPN and CERN. In the range of 1.5 K to 30 K...

  1. Immune System Model Calibration by Genetic Algorithm

    NARCIS (Netherlands)

    Presbitero, A.; Krzhizhanovskaya, V.; Mancini, E.; Brands, R.; Sloot, P.

    2016-01-01

    We aim to develop a mathematical model of the human immune system for advanced individualized healthcare where medication plan is fine-tuned to fit a patient's conditions through monitored biochemical processes. One of the challenges is calibrating model parameters to satisfy existing experimental

  2. Calibrating spectral images using penalized likelihood

    NARCIS (Netherlands)

    Heijden, van der G.W.A.M.; Glasbey, C.

    2003-01-01

    A new method is presented for automatic correction of distortions and for spectral calibration (which band corresponds to which wavelength) of spectral images recorded by means of a spectrograph. The method consists of recording a bar-like pattern with an illumination source with spectral bands

  3. A Calibrated Index of Human Development

    Science.gov (United States)

    Lind, Niels

    2010-01-01

    The weightings of the four component indicators of the UNDP's Human Development Index HDI appear to be arbitrary and have not been given justification. This paper develops a variant of the HDI, calculated to reflect peoples' revealed evaluations of education and the productivity of work. The resulting Calibrated human Development Index CDI has a…

  4. Method and apparatus for calibrating spectrophotometers

    NARCIS (Netherlands)

    Schreutelkamp, F.H.

    2003-01-01

    The present invention relates to a method of calibrating spectrophotometers by placing one or more filters in the light path of the spectrophotometer and measuring the amount of radiation by means of a detector. The present invention furthermore relates to an apparatus to be used with such a method.

  5. Essay on Option Pricing, Hedging and Calibration

    DEFF Research Database (Denmark)

    da Silva Ribeiro, André Manuel

    Quantitative finance is concerned about applying mathematics to financial markets.This thesis is a collection of essays that study different problems in this field: How efficient are option price approximations to calibrate a stochastic volatilitymodel? (Chapter 2) How different is the discretely...

  6. Teaching Camera Calibration by a Constructivist Methodology

    Science.gov (United States)

    Samper, D.; Santolaria, J.; Pastor, J. J.; Aguilar, J. J.

    2010-01-01

    This article describes the Metrovisionlab simulation software and practical sessions designed to teach the most important machine vision camera calibration aspects in courses for senior undergraduate students. By following a constructivist methodology, having received introductory theoretical classes, students use the Metrovisionlab application to…

  7. Retained Gas Sampler Calibration and Simulant Tests

    Energy Technology Data Exchange (ETDEWEB)

    CRAWFORD, B.A.

    2000-01-05

    This test plan provides a method for calibration of the retained gas sampler (RGS) for ammonia gas analysis. Simulant solutions of ammonium hydroxide at known concentrations will be diluted with isotopically labeled 0.04 M ammonium hydroxide solution. Sea sand solids will also be mixed with ammonium hydroxide solution and diluent to determine the accuracy of the system for ammonia gas analysis.

  8. Soil moisture calibration of TDR multilevel probes

    Directory of Open Access Journals (Sweden)

    Serrarens Daniel

    2000-01-01

    Full Text Available Time domain reflectometry (TDR probes are increasingly used for field estimation of soil water content. The objective of this study was to evaluate the accuracy of the multilevel TDR probe under field conditions. For this purpose, eight such TDR probes were installed in small plots that were seeded with beans and sorghum. Data collection from the probes was such that soil moisture readings were automated and logged using a standalone field unit. Neutron probe measurements were used to calibrate the TDR probes. Soil-probe contact and soil compaction were critical to the accuracy of the TDR, especially when a number of TDR probes are combined for a single calibration curve. If each probe is calibrated individually, approximate measurement errors were between 0.005 and 0.015 m³ m-3. However, measurement errors doubled to approximately 0.025 to 0.03 m³ m-3, when TDR probes were combined to yield a single calibration curve.

  9. Champion Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17 min S, 90 deg 33 min W. Champion Island: 1 deg, 15 min S, 90 deg, 05 min W. Urvina...

  10. Direct calibration of PICKY-designed microarrays

    Directory of Open Access Journals (Sweden)

    Ronald Pamela C

    2009-10-01

    Full Text Available Abstract Background Few microarrays have been quantitatively calibrated to identify optimal hybridization conditions because it is difficult to precisely determine the hybridization characteristics of a microarray using biologically variable cDNA samples. Results Using synthesized samples with known concentrations of specific oligonucleotides, a series of microarray experiments was conducted to evaluate microarrays designed by PICKY, an oligo microarray design software tool, and to test a direct microarray calibration method based on the PICKY-predicted, thermodynamically closest nontarget information. The complete set of microarray experiment results is archived in the GEO database with series accession number GSE14717. Additional data files and Perl programs described in this paper can be obtained from the website http://www.complex.iastate.edu under the PICKY Download area. Conclusion PICKY-designed microarray probes are highly reliable over a wide range of hybridization temperatures and sample concentrations. The microarray calibration method reported here allows researchers to experimentally optimize their hybridization conditions. Because this method is straightforward, uses existing microarrays and relatively inexpensive synthesized samples, it can be used by any lab that uses microarrays designed by PICKY. In addition, other microarrays can be reanalyzed by PICKY to obtain the thermodynamically closest nontarget information for calibration.

  11. 40 CFR 1065.310 - Torque calibration.

    Science.gov (United States)

    2010-07-01

    ... the U.S. National Oceanographic and Atmospheric Administration's surface gravity prediction Web site at http://www.ngs.noaa.gov/cgi-bin/grav_pdx.prl. If this Web site is unavailable, you may use the... range. Oscillate or rotate the dynamometer during calibration to reduce frictional static hysteresis...

  12. Planck 2015 results. V. LFI calibration

    CERN Document Server

    Ade, P.A.R.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartolo, N.; Battaglia, P.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.F.; Catalano, A.; Chamballu, A.; Christensen, P.R.; Colombi, S.; Colombo, L.P.L.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Heraud, Y.; Gjerlow, E.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Henrot-Versille, S.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kisner, T.S.; Knoche, J.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Leahy, J.P.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Novikov, D.; Novikov, I.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T.J.; Peel, M.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Pierpaoli, E.; Pietrobon, D.; Pointecouteau, E.; Polenta, G.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renzi, A.; Rocha, G.; Romelli, E.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Stolyarov, V.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Turler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vassallo, T.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Watson, R.; Wehus, I.K.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-01-01

    We present a description of the pipeline used to calibrate the Planck Low Frequency Instrument (LFI) timelines into thermodynamic temperatures for the Planck 2015 data release, covering 4 years of uninterrupted operations. As in the 2013 data release, our calibrator is provided by the spin-synchronous modulation of the CMB dipole, exploiting both the orbital and solar components. Our 2015 LFI analysis provides an independent Solar dipole estimate in excellent agreement with that of HFI and within $1\\sigma$ (0.3 % in amplitude) of the WMAP value. This 0.3 % shift in the peak-to-peak dipole temperature from WMAP and a global overhaul of the iterative calibration code increases the overall level of the LFI maps by 0.45 % (30 GHz), 0.64 % (44 GHz), and 0.82 % (70 GHz) in temperature with respect to the 2013 Planck data release, thus reducing the discrepancy with the power spectrum measured by WMAP. We estimate that the LFI calibration uncertainty is at the level of 0.20 % for the 70 GHz map, 0.26 % for the 44 GHz...

  13. Calibration and characterisation of imaging spectrographs

    NARCIS (Netherlands)

    Polder, G.; Young, I.T.

    2003-01-01

    Spectrograph-based spectral imaging systems provide images with a large number of contiguous spectral channels per pixel. This paper describes the calibration and characterisation of such systems. The relation between pixel position and measured wavelength has been determined using three different

  14. Based on Narcissus of radiometric calibration technology

    Science.gov (United States)

    Jin, Libing; Tang, Shaofan; Liu, Jianfeng; Peng, Honggang

    2015-08-01

    Thermal radiation is an inherent property of all objects. Generally, it is believed that the body, which temperature is above absolute zero, can keep generating infrared radiation. Infrared remote sensing, using of satellite-borne or airborne sensors, collects infrared information to identify the surface feature and inversion of surface parameters, temperature, etc. In order to get more accurately feature information, quantitative measurement is required. Infrared radiometric calibration is one of the key technologies of quantitative infrared remote sensing. Most high-resolution thermal imaging systems are cooling. For the infrared optical system which is having a cooled detector, there are some special phenomenons. Since the temperature of the detector's photosensitive surface is generally low, which is very different from system temperature, it is a very strong cold radiation source. Narcissus refers to the case that the cooled detector can "see" its own reflecting image, which may affect the image quality of infrared system seriously. But for radiometric calibration of satellite-borne infrared camera, it can sometimes take advantage of the narcissus instead of cold cryogenic radiometric calibration. In this paper, the use of narcissus to carry out radiometric calibration is summarized, and simulation results show the feasibility.

  15. Intersectionality, Diversity and Gender

    DEFF Research Database (Denmark)

    Agustin, Lise Rolandsen; Siim, Birte

    2016-01-01

    In the discourses of Danish politicians on ethno-national diversity and integration, the notion of diversity is gendered, especially the articulation of the ‘working woman’ and her labor market participation. Equality, diversity and gender are, thus, intertwined in political, discursive...... constructions of national and European identities/belongings. On this basis the article claims that diversity represents a dual challenge to be conceptualized within and beyond the nation state. The article explores the formation of national and transnational identities based on analyses of political actors......’ debates about gender and diversity within the national and transnational European Polity....

  16. Determining Vitamin D Status: A Comparison between Commercially Available Assays

    Science.gov (United States)

    Snellman, Greta; Melhus, Håkan; Gedeborg, Rolf; Byberg, Liisa; Berglund, Lars; Wernroth, Lisa; Michaëlsson, Karl

    2010-01-01

    Background Vitamin D is not only important for bone health but can also affect the development of several non-bone diseases. The definition of vitamin D insufficiency by serum levels of 25-hydroxyvitamin D depends on the clinical outcome but might also be a consequence of analytical methods used for the definition. Although numerous 25-hydroxyvitamin D assays are available, their comparability is uncertain. We therefore aim to investigate the precision, accuracy and clinical consequences of differences in performance between three common commercially available assays. Methodology/Principal Findings Serum 25-hydroxyvitamin D levels from 204 twins from the Swedish Twin Registry were determined with high-pressure liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS), a radioimmunoassay (RIA) and a chemiluminescent immunoassay (CLIA). High inter-assay disagreement was found. Mean 25-hydroxyvitamin D levels were highest for the HPLC-APCI-MS technique (85 nmol/L, 95% CI 81–89), intermediate for RIA (70 nmol/L, 95% CI 66–74) and lowest with CLIA (60 nmol/L, 95% CI 56–64). Using a 50-nmol/L cut-off, 8% of the subjects were insufficient using HPLC-APCI-MS, 22% with RIA and 43% by CLIA. Because of the heritable component of 25-hydroxyvitamin D status, the accuracy of each method could indirectly be assessed by comparison of within-twin pair correlations. The strongest correlation was found for HPLC-APCI-MS (r = 0.7), intermediate for RIA (r = 0.5) and lowest for CLIA (r = 0.4). Regression analyses between the methods revealed a non-uniform variance (pmethod was HPLC-APCI-MS. Calibration between 25-hydroxyvitamin D assays is intricate. PMID:20644628

  17. Evolvable Cryogenics (ECRYO) Pressure Transducer Calibration Test

    Science.gov (United States)

    Diaz, Carlos E., Jr.

    2015-01-01

    This paper provides a summary of the findings of recent activities conducted by Marshall Space Flight Center's (MSFC) In-Space Propulsion Branch and MSFC's Metrology and Calibration Lab to assess the performance of current "state of the art" pressure transducers for use in long duration storage and transfer of cryogenic propellants. A brief historical narrative in this paper describes the Evolvable Cryogenics program and the relevance of these activities to the program. This paper also provides a review of three separate test activities performed throughout this effort, including: (1) the calibration of several pressure transducer designs in a liquid nitrogen cryogenic environmental chamber, (2) the calibration of a pressure transducer in a liquid helium Dewar, and (3) the calibration of several pressure transducers at temperatures ranging from 20 to 70 degrees Kelvin (K) using a "cryostat" environmental chamber. These three separate test activities allowed for study of the sensors along a temperature range from 4 to 300 K. The combined data shows that both the slope and intercept of the sensor's calibration curve vary as a function of temperature. This homogeneous function is contrary to the linearly decreasing relationship assumed at the start of this investigation. Consequently, the data demonstrates the need for lookup tables to change the slope and intercept used by any data acquisition system. This ultimately would allow for more accurate pressure measurements at the desired temperature range. This paper concludes with a review of a request for information (RFI) survey conducted amongst different suppliers to determine the availability of current "state of the art" flight-qualified pressure transducers. The survey identifies requirements that are most difficult for the suppliers to meet, most notably the capability to validate the sensor's performance at temperatures below 70 K.

  18. An indicator cell assay for blood-based diagnostics.

    Directory of Open Access Journals (Sweden)

    Samuel A Danziger

    Full Text Available We have established proof of principle for the Indicator Cell Assay Platform™ (iCAP™, a broadly applicable tool for blood-based diagnostics that uses specifically-selected, standardized cells as biosensors, relying on their innate ability to integrate and respond to diverse signals present in patients' blood. To develop an assay, indicator cells are exposed in vitro to serum from case or control subjects and their global differential response patterns are used to train reliable, disease classifiers based on a small number of features. In a feasibility study, the iCAP detected pre-symptomatic disease in a murine model of amyotrophic lateral sclerosis (ALS with 94% accuracy (p-Value = 3.81E-6 and correctly identified samples from a murine Huntington's disease model as non-carriers of ALS. Beyond the mouse model, in a preliminary human disease study, the iCAP detected early stage Alzheimer's disease with 72% cross-validated accuracy (p-Value = 3.10E-3. For both assays, iCAP features were enriched for disease-related genes, supporting the assay's relevance for disease research.

  19. LIDAR Velodyne HDL-64E Calibration Using Pattern Planes

    Directory of Open Access Journals (Sweden)

    Gerardo Atanacio-Jiménez

    2011-11-01

    Full Text Available This work describes a method for calibration of the Velodyne HDL‐64E scanning LIDAR system. The principal contribution was expressed by a pattern calibration signature, the mathematical model and the numerical algorithm for computing the calibration parameters of the LIDAR. In this calibration pattern the main objective is to minimize systematic errors due to geometric calibration factor. It describes an algorithm for solution of the intrinsic and extrinsic parameters. Finally, its uncertainty was calculated from the standard deviation of calibration result errors.

  20. Sensor Calibration Design Based on D-Optimality Criterion

    Directory of Open Access Journals (Sweden)

    Hajiyev Chingiz

    2016-09-01

    Full Text Available In this study, a procedure for optimal selection of measurement points using the D-optimality criterion to find the best calibration curves of measurement sensors is proposed. The coefficients of calibration curve are evaluated by applying the classical Least Squares Method (LSM. As an example, the problem of optimal selection for standard pressure setters when calibrating a differential pressure sensor is solved. The values obtained from the D-optimum measurement points for calibration of the differential pressure sensor are compared with those from actual experiments. Comparison of the calibration errors corresponding to the D-optimal, A-optimal and Equidistant calibration curves is done.

  1. Linking Diversity and Differentiation

    Directory of Open Access Journals (Sweden)

    Hans-Rolf Gregorius

    2010-03-01

    Full Text Available Generally speaking, the term differentiation refers to differences between collections for the distribution of specified traits of their members, while diversity deals with (effective numbers of trait states (types. Counting numbers of types implies discrete traits such as alleles and genotypes in population genetics or species and taxa in ecology. Comparisons between the concepts of differentiation and diversity therefore primarily refer to discrete traits. Diversity is related to differentiation through the idea that the total diversity of a subdivided collection should be composed of the diversity within the subcollections and a complement called “diversity between subcollections”. The idea goes back to the perception that the mixing of differentiated collections increases diversity. Several existing concepts of “diversity between subcollections” are based on this idea. Among them, β-diversity and fixation (inadvertently called differentiation are the most prominent in ecology and in population genetics, respectively. The pertaining measures are shown to quantify the effect of differentiation in terms of diversity components, though from a dual perspective: the classical perspective of differentiation between collections for their type compositions, and the reverse perspective of differentiation between types for their collection affiliations. A series of measures of diversity-oriented differentiation is presented that consider this dual perspective at two levels of diversity partitioning: the overall type or subcollection diversity and the joint type-subcollection diversity. It turns out that, in contrast with common notions, the measures of fixation (such as FST or GST refer to the perspective of type rather than subcollection differentiation. This unexpected observation strongly suggests that the popular interpretations of fixation measures must be reconsidered.

  2. Performance characteristics of the Beckman Coulter UniCel DxI 800 TSH (3rd IS) assay.

    Science.gov (United States)

    Winston-McPherson, Gabrielle N; Samraj, Annie N; Poster, Kristina; Yamaguchi, Diane; Dickerson, Jane A; Drees, Julia C; Holmes, Daniel T; Greene, Dina N

    2018-03-01

    Beckman Coulter recently reformulated their commercial TSH assay with primary calibration to the World Health Organization 3rd TSH international standard. An extensive evaluation of the performance characteristics for this assay was completed. Intra-day and inter-day precision was evaluated using 3 concentrations of commercial quality control material. Linearity, reportable range, stability, sensitivity and susceptibility to common inferences were determined using pooled patient specimens. Inter-assay variability was assessed across 5 different platforms (n=47 patient specimens). Intra-day and inter-day CVs were UniCel DxI 800, is precise, highly sensitive and comparable to the previous generation assay. The assay is acceptable for clinical testing. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Antioxidants and the Comet assay.

    Science.gov (United States)

    Cemeli, Eduardo; Baumgartner, Adolf; Anderson, Diana

    2009-01-01

    It is widely accepted that antioxidants, either endogenous or from the diet, play a key role in preserving health. They are able to quench radical species generated in situations of oxidative stress, either triggered by pathologies or xenobiotics, and they protect the integrity of DNA from genotoxicants. Nevertheless, there are still many compounds with unclear or unidentified prooxidant/antioxidant activities. This is of concern since there is an increase in the number of compounds synthesized or extracted from vegetables to which humans might be exposed. Despite the well-established protective effects of fruit and vegetables, the antioxidant(s) responsible have not all been clearly identified. There might also be alternative mechanisms contributing to the protective effects for which a comprehensive description is lacking. In the last two decades, the Comet assay has been extensively used for the investigation of the effects of antioxidants and many reports can be found in the literature. The Comet assay, a relatively fast, simple, and sensitive technique for the analysis of DNA damage in all cell types, has been applied for the screening of chemicals, biomonitoring and intervention studies. In the present review, several of the most well-known antioxidants are considered. These include: catalase, superoxide dismutase, glutathione peroxidase, selenium, iron chelators, melatonin, melanin, vitamins (A, B, C and E), carotenes, flavonoids, isoflavones, tea polyphenols, wine polyphenols and synthetic antioxidants. Investigations showing beneficial as well as non-beneficial properties of the antioxidants selected, either at the in vitro, ex vivo or in vivo level are discussed.

  4. SNO+ Scintillator Purification and Assay

    Science.gov (United States)

    Ford, R.; Chen, M.; Chkvorets, O.; Hallman, D.; Vázquez-Jáuregui, E.

    2011-04-01

    We describe the R&D on the scintillator purification and assay methods and technology for the SNO+ neutrino and double-beta decay experiment. The SNO+ experiment is a replacement of the SNO heavy water with liquid scintillator comprised of 2 g/L PPO in linear alkylbenzene (LAB). During filling the LAB will be transported underground by rail car and purified by multi-stage distillation and steam stripping at a flow rate of 19 LPM. While the detector is operational the scintillator can be recirculated at 150 LPM (full detector volume in 4 days) to provide repurification as necessary by either water extraction (for Ra, K, Bi) or by functional metal scavenger columns (for Pb, Ra, Bi, Ac, Th) followed by steam stripping to remove noble gases and oxygen (Rn, O2, Kr, Ar). The metal scavenger columns also provide a method for scintillator assay for ex-situ measurement of the U and Th chain radioactivity. We have developed "natural" radioactive spikes of Pb and Ra in LAB and use these for purification testing. Lastly, we present the planned operating modes and purification strategies and the plant specifications and design.

  5. Reporter Gene Assays in Ecotoxicology.

    Science.gov (United States)

    Elad, Tal; Belkin, Shimshon

    The need for simple and rapid means for evaluating the potential toxic effects of environmental samples has prompted the development of reporter gene assays, based on tester cells (bioreporters) genetically engineered to report on sample toxicity by producing a readily quantifiable signal. Bacteria are especially suitable to serve as bioreporters owing to their fast responses, low cost, convenient preservation, ease of handling, and amenability to genetic manipulations. Various bacterial bioreporters have been introduced for general toxicity and genotoxicity assessment, and the monitoring of endocrine disrupting and dioxin-like compounds has been mostly covered by similarly engineered eukaryotic cells. Some reporter gene assays have been validated, standardized, and accredited, and many others are under constant development. Efforts are aimed at broadening detection spectra, lowering detection thresholds, and combining toxicity identification capabilities with characterization of the toxic effects. Taking advantage of bacterial robustness, attempts are also being made to incorporate bacterial bioreporters into field instrumentation for online continuous monitoring or on-site spot checks. However, key hurdles concerning test validation, cell preservation, and regulatory issues related to the use of genetically modified organisms still remain to be overcome.

  6. Cross-calibration of liquid and solid QCT calibration standards: corrections to the UCSF normative data

    Science.gov (United States)

    Faulkner, K. G.; Gluer, C. C.; Grampp, S.; Genant, H. K.

    1993-01-01

    Quantitative computed tomography (QCT) has been shown to be a precise and sensitive method for evaluating spinal bone mineral density (BMD) and skeletal response to aging and therapy. Precise and accurate determination of BMD using QCT requires a calibration standard to compensate for and reduce the effects of beam-hardening artifacts and scanner drift. The first standards were based on dipotassium hydrogen phosphate (K2HPO4) solutions. Recently, several manufacturers have developed stable solid calibration standards based on calcium hydroxyapatite (CHA) in water-equivalent plastic. Due to differences in attenuating properties of the liquid and solid standards, the calibrated BMD values obtained with each system do not agree. In order to compare and interpret the results obtained on both systems, cross-calibration measurements were performed in phantoms and patients using the University of California San Francisco (UCSF) liquid standard and the Image Analysis (IA) solid standard on the UCSF GE 9800 CT scanner. From the phantom measurements, a highly linear relationship was found between the liquid- and solid-calibrated BMD values. No influence on the cross-calibration due to simulated variations in body size or vertebral fat content was seen, though a significant difference in the cross-calibration was observed between scans acquired at 80 and 140 kVp. From the patient measurements, a linear relationship between the liquid (UCSF) and solid (IA) calibrated values was derived for GE 9800 CT scanners at 80 kVp (IA = [1.15 x UCSF] - 7.32).(ABSTRACT TRUNCATED AT 250 WORDS).

  7. Subsurface Flow Model Calibration under Uncertain Geologic Scenarios with Adaptive Sparse Reconstruction Techniques

    Science.gov (United States)

    Khaninezhad, M. M.; Jafarpour, B.

    2013-12-01

    Construction of predictive aquifer and reservoir models involves subjective interpretation and interpolation of spatially limited data and imperfect modeling assumptions. Hence, the process can introduce significant uncertainty and bias into subsurface flow and transport modeling. In particular, the uncertainty in the geologic continuity model can markedly degrade the quality of fluid displacement predictions and, hence, the efficiency of resource development plans. We present a novel approach for flow model calibration under uncertainty in geologic continuity model. Our approach is inspired by recent advances in sparse reconstruction and takes advantage of the selection property of the l1-norm minimization in sparse bases. Using an adaptive saprse reconstruction framework, we develop a prior model identification method to discriminate against distinct prior geologic continuity models (e.g., variograms) that are proposed for model calibration. Realizations from each geologic continuity model are used to generate a diverse geologic dictionary that compactly represents models from each proposed prior geologic scenario. The inversion method is initialized by taking the same number of elements from each prior geologic continuity model. At each iteration of the nonlinear model calibration process the contribution of the proposed prior models to the reconstructed solution is monitored and, to improve the solution quality, elements from inconsistent prior models are replaced with additional elements from geologically consistent priors. We use several numerical examples to illustrate the effectiveness of the proposed adaptive prior identification approach for model calibration under uncertainty in prior geologic continuity.

  8. CALIBRATION PROCEDURES IN MID FORMAT CAMERA SETUPS

    Directory of Open Access Journals (Sweden)

    F. Pivnicka

    2012-07-01

    Full Text Available A growing number of mid-format cameras are used for aerial surveying projects. To achieve a reliable and geometrically precise result also in the photogrammetric workflow, awareness on the sensitive parts is important. The use of direct referencing systems (GPS/IMU, the mounting on a stabilizing camera platform and the specific values of the mid format camera make a professional setup with various calibration and misalignment operations necessary. An important part is to have a proper camera calibration. Using aerial images over a well designed test field with 3D structures and/or different flight altitudes enable the determination of calibration values in Bingo software. It will be demonstrated how such a calibration can be performed. The direct referencing device must be mounted in a solid and reliable way to the camera. Beside the mechanical work especially in mounting the camera beside the IMU, 2 lever arms have to be measured in mm accuracy. Important are the lever arms from the GPS Antenna to the IMU's calibrated centre and also the lever arm from the IMU centre to the Camera projection centre. In fact, the measurement with a total station is not a difficult task but the definition of the right centres and the need for using rotation matrices can cause serious accuracy problems. The benefit of small and medium format cameras is that also smaller aircrafts can be used. Like that, a gyro bases stabilized platform is recommended. This causes, that the IMU must be mounted beside the camera on the stabilizer. The advantage is, that the IMU can be used to control the platform, the problematic thing is, that the IMU to GPS antenna lever arm is floating. In fact we have to deal with an additional data stream, the values of the movement of the stabiliser to correct the floating lever arm distances. If the post-processing of the GPS-IMU data by taking the floating levers into account, delivers an expected result, the lever arms between IMU and

  9. Calibrating animal-borne proximity loggers.

    Science.gov (United States)

    Rutz, Christian; Morrissey, Michael B; Burns, Zackory T; Burt, John; Otis, Brian; St Clair, James J H; James, Richard

    2015-06-01

    Growing interest in the structure and dynamics of animal social networks has stimulated efforts to develop automated tracking technologies that can reliably record encounters in free-ranging subjects. A particularly promising approach is the use of animal-attached 'proximity loggers', which collect data on the incidence, duration and proximity of spatial associations through inter-logger radio communication. While proximity logging is based on a straightforward physical principle - the attenuation of propagating radio waves with distance - calibrating systems for field deployment is challenging, since most study species roam across complex, heterogeneous environments.In this study, we calibrated a recently developed digital proximity-logging system ('Encounternet') for deployment on a wild population of New Caledonian crows Corvus moneduloides. Our principal objective was to establish a quantitative model that enables robust post hoc estimation of logger-to-logger (and, hence, crow-to-crow) distances from logger-recorded signal-strength values. To achieve an accurate description of the radio communication between crow-borne loggers, we conducted a calibration exercise that combines theoretical analyses, field experiments, statistical modelling, behavioural observations, and computer simulations.We show that, using signal-strength information only, it is possible to assign crow encounters reliably to predefined distance classes, enabling powerful analyses of social dynamics. For example, raw data sets from field-deployed loggers can be filtered at the analysis stage to include predominantly encounters where crows would have come to within a few metres of each other, and could therefore have socially learned new behaviours through direct observation. One of the main challenges for improving data classification further is the fact that crows - like most other study species - associate across a wide variety of habitats and behavioural contexts, with different signal

  10. Development and evaluation of a fluorescence microplate assay for quantification of heparins and other sulfated carbohydrates.

    Science.gov (United States)

    Lühn, Susanne; Schrader, Thomas; Sun, Wei; Alban, Susanne

    2010-05-01

    Due to their complex composition, quantification of heparins is difficult. On the one hand there are many biological tests, which only indirectly detect effects of the antithrombin-binding material. On the other hand direct quantitative methods are available but they are often insensitive, challenging, time-consuming or expensive. The aim of this study was to develop a sensitive, rapid, simple as well as inexpensive direct quantification assay suitable for routine analysis. Based on Polymer-H, a novel heparin complexing, fluorescent labeled synthetic polymer (lambda((ex)) 320nm, lambda((em)) 510nm), a microplate assay was developed and optimized. The specificity of the assay was evaluated by structure-assay response relationships studies using structurally defined glucan sulfates, heparins, and other natural and synthetic sulfated carbohydrates. The fluorescence intensity of Polymer-H (7.5microg/ml) showed to be concentration-dependently amplified by heparins as well as by other sulfated carbohydrates. The best sensitivity, accuracy and linearity were observed in a range from 0.63 to 5.0microg/ml heparins. No differences in the fluorescence between various heparins were observed, so that only one calibration curve is needed. In addition, all types of carbohydrates with a degree of sulfation (DS)> approximately 1.2 and a M(r)>3000 can be quantified as well. By own calibration curves also other sulfated carbohydrates like fondaparinux or other glycosaminoglycans (DS>0.4) can be determined. Copyright 2009 Elsevier B.V. All rights reserved.

  11. Spectral and Radiometric Calibration using Tunable Lasers Project

    Data.gov (United States)

    National Aeronautics and Space Administration —  SIRCUS-based calibration relies on a set of monitoring radiometers and tunable laser sources to provide an absolute radiometric calibration that can approach...

  12. Calibration Base Lines for Electronic Distance Measuring Instruments (EDMI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A calibration base line (CBL) is a precisely measured, straight-line course of approximately 1,400 m used to calibrate Electronic Distance Measuring Instruments...

  13. Quantifying uncertainty contributions for fibre optic power meter calibrations

    CSIR Research Space (South Africa)

    Nel, M

    2009-09-01

    Full Text Available A fibre optic power meter calibration has several uncertainty contributors associated with it. In order to assign a realistic uncertainty to the calibration result it is necessary to realistically estimate the magnitude of each uncertainty...

  14. 40 CFR 92.120 - NDIR analyzer calibration and checks.

    Science.gov (United States)

    2010-07-01

    ...) of this section, determine the saturation vapor pressure. (7) Calculate the water concentration (Z... instructions for initial start-up and basic operating adjustments. (2) Calibration curve. Develop a calibration... for each range by the spanning process. ...

  15. Acoustic Calibration and Trials (HB0707, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Operational objectives are to: (1) calibrate the EK60 Scientific Sounder, (2) calibrate the ME70, (3) collect acoustic data during the transit, (4) evaluate and...

  16. Instrument calibration architecture of Radar Imaging Satellite (RISAT-1)

    Science.gov (United States)

    Misra, T.; Bhan, R.; Putrevu, D.; Mehrotra, P.; Nandy, P. S.; Shukla, S. D.; Rao, C. V. N.; Dave, D. B.; Desai, N. M.

    2016-05-01

    Radar Imaging Satellite (RISAT-1) payload system is configured to perform self-calibration of transmit and receive paths before and after imaging sessions through a special instrument calibration technique. Instrument calibration architecture of RISAT-1 supported ground verification and validation of payload including active array antenna. During on-ground validation of 126 beams of active array antenna which needed precise calibration of boresight pointing, a unique method called "collimation coefficient error estimation" was utilized. This method of antenna calibration was supported by special hardware and software calibration architecture of RISAT-1. This paper concentrates on RISAT-1 hardware and software architecture which supports in-orbit and on-ground instrument calibration. Efforts are also put here to highlight use of special calibration scheme of RISAT-1 instrument to evaluate system response during ground verification and validation.

  17. 40 CFR 91.425 - CVS calibration frequency.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.425 CVS calibration frequency. Calibrate the CVS positive displacement pump or critical flow venturi...

  18. 40 CFR 90.425 - CVS calibration frequency.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Gaseous Exhaust Test Procedures § 90.425 CVS calibration frequency. Calibrate the CVS positive displacement pump or...

  19. AIRS/Aqua Level 1B Calibration subset V005

    Data.gov (United States)

    National Aeronautics and Space Administration — AIRS/Aqua Level-1B calibration subset including clear cases, special calibration sites, random nadir spots, and high clouds. The Atmospheric Infrared Sounder (AIRS)...

  20. Infrared stereo calibration for unmanned ground vehicle navigation

    Science.gov (United States)

    Harguess, Josh; Strange, Shawn

    2014-06-01

    The problem of calibrating two color cameras as a stereo pair has been heavily researched and many off-the-shelf software packages, such as Robot Operating System and OpenCV, include calibration routines that work in most cases. However, the problem of calibrating two infrared (IR) cameras for the purposes of sensor fusion and point could generation is relatively new and many challenges exist. We present a comparison of color camera and IR camera stereo calibration using data from an unmanned ground vehicle. There are two main challenges in IR stereo calibration; the calibration board (material, design, etc.) and the accuracy of calibration pattern detection. We present our analysis of these challenges along with our IR stereo calibration methodology. Finally, we present our results both visually and analytically with computed reprojection errors.

  1. Self-Calibrating Vector Helium Magnetometer (SVHM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase 2 SBIR proposal describes the design, fabrication and calibration of a brass-board Self-Calibrating Vector Helium Magnetometer (SVHM). The SVHM instrument...

  2. Aspects of the SMOS Pre-launch Calibration

    DEFF Research Database (Denmark)

    Skou, Niels

    2003-01-01

    A synthetic aperture radiometer system, SMOS, is under development for launch in 2007. The synthetic aperture concept requires calibration activities of novel nature in addition to traditional radiometer calibration exercises. Especially very accurate antenna pattern measurements are an issue....

  3. Weed Control Sprayers: Calibration and Maintenance. Special Circular 81.

    Science.gov (United States)

    Myers, Arthur L.

    This manual covers aspects of calibration and maintenance of weed control sprayers including variables affecting application rate, the pre-calibration check, calculations, band spraying, nozzle tip selection, agitation, and cleaning. (BB)

  4. In vivo transgenic mutation assays.

    Science.gov (United States)

    Thybaud, Véronique; Dean, Stephen; Nohmi, Takehiko; de Boer, Johan; Douglas, George R; Glickman, Barry W; Gorelick, Nancy J; Heddle, John A; Heflich, Robert H; Lambert, Iain; Martus, Hans-Jörg; Mirsalis, Jon C; Suzuki, Takayoshi; Yajima, Nobuhiro

    2003-10-07

    Transgenic rodent gene-mutation models provide relatively quick and statistically reliable assays for gene mutations in the DNA from any tissue. This report summarizes those issues that have been agreed upon at a previous IWGT meeting [Environ. Mol. Mutagen. 35 (2000) 253], and discusses in depth those issues for which no consensus was reached before. It was previously agreed that for regulatory applications, assays should be based upon neutral genes, be generally available in several laboratories, and be readily transferable. For phage-based assays, five to ten animals per group should be analyzed, assuming a spontaneous mutant frequency (MF) of approximately 3x10(-5) mutants/locus and 125,000-300,000 plaque or colony forming units (pfu or cfu) per tissue per animal. A full set of data should be generated for a vehicle control and two dose groups. Concurrent positive control animals are only necessary during validation, but positive control DNA must be included in each plating. Tissues should be processed and analyzed in a blocked design, where samples from negative control, positive control and each treatment group are processed together. The total number of pfus or cfus and the MF for each tissue and animal are reported. Statistical tests should consider the animal as the experimental unit. Nonparametric statistical tests are recommended. A positive result is a statistically significant dose-response and/or statistically significant increase in any dose group compared to concurrent negative controls using an appropriate statistical model. A negative result is a statistically non-significant change, with all mean MFs within two standard deviations of the control. During the current workshop, a general protocol was agreed in which animals are treated daily for 28 consecutive days and tissues sampled 3 days after the final treatment. This recommendation could be modified by reducing or increasing the number of treatments or the length of the treatment period, when

  5. Managing Protean Diversity

    DEFF Research Database (Denmark)

    Marfelt, Mikkel Mouritz; Muhr, Sara Louise

    2016-01-01

    Recently, global workforce diversity and its management have received criticism for not paying attention to the contextual influence stemming from socially constructed dialectics of power and politics. These contextual dynamics, however, tend to be viewed as external to the organization. In this ......, we develop the concept of protean diversity to better understand how to manage the ever-changing and unstable nature of contemporary workforce diversity.......Recently, global workforce diversity and its management have received criticism for not paying attention to the contextual influence stemming from socially constructed dialectics of power and politics. These contextual dynamics, however, tend to be viewed as external to the organization....... In this article, we follow the call for critically investigating the contexts influencing diversity management by analyzing the development of a global human resource management project initiated to promote a culturally diverse workforce. We find that despite good intentions, as well as support from the top...

  6. Reproducibility and calibration of MMC-based high-resolution gamma detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bates, C. R.; Friedrich, S., E-mail: friedrich1@llnl.gov [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States); Pies, C.; Kempf, S.; Hengstler, D.; Fleischmann, A.; Gastaldo, L.; Enss, C. [Kirchhoff-Institut für Physik, Universität Heidelberg, Im Neuenheimer Feld 227, D-69120 Heidelberg (Germany)

    2016-07-11

    We describe a prototype γ-ray detector based on a metallic magnetic calorimeter with an energy resolution of 46 eV at 60 keV and a reproducible response function that follows a simple second-order polynomial. The simple detector calibration allows adding high-resolution spectra from different pixels and different cool-downs without loss in energy resolution to determine γ-ray centroids with high accuracy. As an example of an application in nuclear safeguards enabled by such a γ-ray detector, we discuss the non-destructive assay of {sup 242}Pu in a mixed-isotope Pu sample.

  7. Is diversity good?

    OpenAIRE

    Bouville, Mathieu

    2007-01-01

    Prominent ethical and policy issues such as affirmative action and female enrollment in science and engineering revolve around the idea that diversity is good. However, even though diversity is an ambiguous concept, a precise definition is seldom provided. We show that diversity may be construed as a factual description, a craving for symmetry, an intrinsic good, an instrumental good, a symptom, or a side effect. These acceptions differ vastly in their nature and properties. The first one can...

  8. Dealing with Diversity

    Directory of Open Access Journals (Sweden)

    Benjamin Levin

    1994-01-01

    Full Text Available Increasing diversity in the population is a major issue for educators in North America, presenting political as well as educational challenges. This paper examines Canadian educational policy responses to four kinds of diversity - bilingualism (French/English, multiculturalism, the situation of aboriginal peoples, and the problem of poverty. A description of each issue leads to some speculations or propositions on the nature of diversity and appropriate educational responses to it.

  9. Diversity in marketing practice

    OpenAIRE

    Torres, Ann Marie

    2009-01-01

    Theory development in marketing has received periodic debate. In the spirit of reappraisal, this thesis endeavours to explain the nature of diversity in marketing practice found among firms and the manner in which marketing practice is related to organisational performance. The specific research goals are to explore: the nature of diversity in marketing practice, as linked to strategic archetypes; whether there is evidence of order in the diversity of marketing practice that can be linked to ...

  10. Small Scale Mass Flow Plug Calibration

    Science.gov (United States)

    Sasson, Jonathan

    2015-01-01

    A simple control volume model has been developed to calculate the discharge coefficient through a mass flow plug (MFP) and validated with a calibration experiment. The maximum error of the model in the operating region of the MFP is 0.54%. The model uses the MFP geometry and operating pressure and temperature to couple continuity, momentum, energy, an equation of state, and wall shear. Effects of boundary layer growth and the reduction in cross-sectional flow area are calculated using an in- integral method. A CFD calibration is shown to be of lower accuracy with a maximum error of 1.35%, and slower by a factor of 100. Effects of total pressure distortion are taken into account in the experiment. Distortion creates a loss in flow rate and can be characterized by two different distortion descriptors.

  11. SURFplus Model Calibration for PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-12-06

    The SURFplus reactive burn model is calibrated for the TATB based explosive PBX 9502 at three initial temperatures; hot (75 C), ambient (23 C) and cold (-55 C). The CJ state depends on the initial temperature due to the variation in the initial density and initial specific energy of the PBX reactants. For the reactants, a porosity model for full density TATB is used. This allows the initial PBX density to be set to its measured value even though the coeffcient of thermal expansion for the TATB and the PBX differ. The PBX products EOS is taken as independent of the initial PBX state. The initial temperature also affects the sensitivity to shock initiation. The model rate parameters are calibrated to Pop plot data, the failure diameter, the limiting detonation speed just above the failure diameters, and curvature effect data for small curvature.

  12. Stable Targets for Spaceborne Microwave Radiometer Calibration

    Science.gov (United States)

    Njoku, Eni G.; Chan, S. K.; Armstrong, R. L.; Brodzik, M. J.; Savoie, M. H.; Knowles, K.

    2006-01-01

    Beginning in the 1970s, continuous observations of the Earth have been made by spaceborne microwave radiometers. Since these instruments have different observational characteristics, care must be taken in combining their data to form consistent long term records of brightness temperatures and derived geophysical quantities. To be useful for climate studies, data from different instruments must be calibrated relative to each other and to reference targets on the ground whose characteristics are stable and can be monitored continuously. Identifying such targets over land is not straightforward due to the heterogeneity and complexity of the land surface and cover. In this work, we provide an analysis of multi-sensor brightness temperature statistics over ocean, tropical forest, and ice sheet locations, spanning the period from 1978 to the present, and indicate the potential of these sites as continuous calibration monitoring targets.

  13. Cost effective robust rule calibration system

    Directory of Open Access Journals (Sweden)

    Greeff P.

    2014-01-01

    Full Text Available One of the main calibration services of African NMIs (National Metrology Institutes is the measurement of tapes and rules. This is mainly regulated by legal metrology and OIML (International Organisation of Legal Metrology specifications are therefore referenced. Specifically, OIML R-35 is the standard to which rules or line scales must conform. The accuracy of most African NMIs systems however, cannot prove conformance to this specification. This article will detail the development of a new, cost effective, line scale calibration system, which will have accuracy better than the specification prescribed. The system was locally developed and its design is based on off-the-shelf components and open source software. It is also ready-for-upgrade to an absolute system. The system and details of the line detection algorithm will be presented.

  14. Laser calibration of the ATLAS Tile Calorimeter

    CERN Document Server

    Di Gregorio, Giulia; The ATLAS collaboration

    2017-01-01

    High performance stability of the ATLAS Tile calorimeter is achieved with a set of calibration procedures. One step of the calibrtion procedure is based on measurements of the response stability to laser excitation of the photomultipliers (PMTs) that are used to readout the calorimeter cells. A facility to study in lab the PMT stability response is operating in the PISA-INFN laboratories since 2015. Goals of the test in lab are to study the time evolution of the PMT response to reproduce and to understand the origin of the resonse drifts seen with the PMT mounted on the Tile calorimeter in its normal operation during LHC run I and run II. A new statistical approach was developed to measure the drift of the absolute gain. This approach was applied to both the ATLAS laser calibration data and to the data collected in the Pisa local laboratory. The preliminary results from these two studies are shown.

  15. An Improved Metallicity Calibration with UBV Photometry

    Science.gov (United States)

    Karaali, S.; Bilir, S.; Ak, S.; Yaz, E.; Coşkunoğlu, B.

    2011-06-01

    We used the data of 701 stars covering the colour index interval 0.32PASTEL catalogue and estimated metallicity-dependent guillotine factors, which provide a more accurate metallicity calibration. We reduced the metallicities of 11 different authors to the metallicities of Valenti & Fischer (2005), and thus obtained a homogeneous set of data which increased the accuracy of the calibration, i.e. [Fe/H]=-14.316δ0.6 2-3.557δ0.6+0.105. Comparison of the metallicity residuals for two sets of data based on the metallicity-dependent guillotine factors with the ones obtained via metal-free guillotine factors shows that metallicities estimated by means of the new guillotine factors are more accurate than the other ones. This advantage can be used in the metallicity gradient investigation of the Galactic components, i.e. thin disc, thick disc, and halo.

  16. Self Calibrated Wireless Distributed Environmental Sensory Networks

    Science.gov (United States)

    Fishbain, Barak; Moreno-Centeno, Erick

    2016-04-01

    Recent advances in sensory and communication technologies have made Wireless Distributed Environmental Sensory Networks (WDESN) technically and economically feasible. WDESNs present an unprecedented tool for studying many environmental processes in a new way. However, the WDESNs’ calibration process is a major obstacle in them becoming the common practice. Here, we present a new, robust and efficient method for aggregating measurements acquired by an uncalibrated WDESN, and producing accurate estimates of the observed environmental variable’s true levels rendering the network as self-calibrated. The suggested method presents novelty both in group-decision-making and in environmental sensing as it offers a most valuable tool for distributed environmental monitoring data aggregation. Applying the method on an extensive real-life air-pollution dataset showed markedly more accurate results than the common practice and the state-of-the-art.

  17. FY07 Final Report for Calibration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L.; Broocks, Bryan T.; Cannon, Bret D.; Ho, Nicolas

    2007-12-01

    Remote infrared (IR) sensing provides a valuable method for detection and identification of materials associated with nuclear proliferation. Current challenges for remote sensors include minimizing the size, mass, and power requirements for cheaper, smaller, and more deployable instruments without affecting the measurement performance. One area that is often overlooked is sensor calibration design that is optimized to minimize the cost, size, weight, and power of the payload. Yet, an on-board calibration system is essential to account for changes in the detector response once the instrument has been removed from the laboratory. The Calibration Systems project at Pacific Northwest National Laboratory (PNNL) is aimed towards developing and demonstrating compact quantum cascade (QC) laser-based calibration systems for infrared sensor systems in order to provide both a spectral and radiometric calibration while minimizing the impact on the instrument payload. In FY05, PNNL demonstrated a multi-level radiance scheme that provides six radiance levels for an enhanced linearity check compared to the currently accepted two-point scheme. PNNL began testing the repeatability of this scheme using a cryogenically cooled, single-mode quantum cascade laser (QCL). A cyclic variation in the power was observed that was attributed to the thermal cycling of the laser's dewar. In FY06, PNNL continued testing this scheme and installed an auxiliary liquid nitrogen reservoir to limit the thermal cycling effects. Although better repeatability was achieved over a longer time period, power fluctuations were still observed due to the thermal cycling. Due to the limitations with the cryogenic system, PNNL began testing Fabry-Perot QCLs that operate continuous-wave (cw) or quasi-cw at room temperature (RT) in FY06. PNNL demonstrated a multi-level scheme that provides five radiance levels in 105 seconds with excellent repeatability. We have continued testing this repeatability in FY07. A

  18. Modeling and Calibration of Automatic Guided Vehicle

    Science.gov (United States)

    Sawada, Kenji; Tanaka, Kosuke; Shin, Seiichi; Kumagai, Kenji; Yoneda, Hisato

    This paper presents a modeling of an automatic guided vehicle (AGV) to achieve a model-based control. The modeling includes 3 kinds of choices; a choice of input-output data pair from 14 candidate pairs, a choice of system identification technique form 5 candidate techniques, a choice of discrete to continuous transform method from 2 candidate methods. In order to obtain reliable plant models of AGV, an approach for calibration between a statistical model and a physical model is also here. In our approach, the models are combined according to the weight of AGV. As a result, our calibration problem is recast as a nonlinear optimization problem that can be solved by quasi-Newton's method.

  19. Calibration of optical particle-size analyzer

    Science.gov (United States)

    Pechin, William H.; Thacker, Louis H.; Turner, Lloyd J.

    1979-01-01

    This invention relates to a system for the calibration of an optical particle-size analyzer of the light-intercepting type for spherical particles, wherein a rotary wheel or disc is provided with radially-extending wires of differing diameters, each wire corresponding to a particular equivalent spherical particle diameter. These wires are passed at an appropriate frequency between the light source and the light detector of the analyzer. The reduction of light as received at the detector is a measure of the size of the wire, and the electronic signal may then be adjusted to provide the desired signal for corresponding spherical particles. This calibrator may be operated at any time without interrupting other processing.

  20. Dynamic water vapor and temperature calibration system.

    Science.gov (United States)

    Montague, F W; Primiano, F P; Saidel, G M

    1984-06-01

    The objective evaluation of thermal and humidification processes in the pulmonary system requires accurate dynamic measurements of temperature and water vapor concentration of a flowing gas mixture. The adequacy of instruments used for such measurements can only be determined by dynamic calibration techniques. We have developed a method of producing step changes in temperature and water vapor content of a gas mixture undergoing controlled steady flow. The system consists of two reservoirs and a slide valve that switches a test section between them. The inlet (usually a probe or catheter tip) of the device to be calibrated is positioned in the test section. The flow rate through the test section is minimally changed during the transition between gas from one reservoir to that of the other. The system has been used to analyze the response of a thermistor and a respiratory mass spectrometer to changes in gas temperature and water vapor.

  1. Automated system for the calibration of magnetometers

    DEFF Research Database (Denmark)

    Petrucha, Vojtech; Kaspar, Petr; Ripka, Pavel

    2009-01-01

    University. There are three axes of rotation in this design (compared to two axes in the previous version). The addition of the third axis allows us to calibrate more complex devices. An electronic compass based on a vector fluxgate magnetometer and micro electro mechanical systems (MEMS) accelerometer...... is one example. The new platform can also be used to evaluate the parameters of the compass in all possible variations in azimuth, pitch, and roll. The system is based on piezoelectric motors, which are placed on a platform made of aluminum, brass, plastic, and glass. Position sensing is accomplished...... through custom-made optical incremental sensors. The system is controlled by a microcontroller, which executes commands from a computer. The properties of the system as well as calibration and measurement results will be presented. ©2009 American Institute of Physics...

  2. Relevance of ellipse eccentricity for camera calibration

    Science.gov (United States)

    Mordwinzew, W.; Tietz, B.; Boochs, F.; Paulus, D.

    2015-05-01

    Plane circular targets are widely used within calibrations of optical sensors through photogrammetric set-ups. Due to this popularity, their advantages and disadvantages are also well studied in the scientific community. One main disadvantage occurs when the projected target is not parallel to the image plane. In this geometric constellation, the target has an elliptic geometry with an offset between its geometric and its projected center. This difference is referred to as ellipse eccentricity and is a systematic error which, if not treated accordingly, has a negative impact on the overall achievable accuracy. The magnitude and direction of eccentricity errors are dependent on various factors. The most important one is the target size. The bigger an ellipse in the image is, the bigger the error will be. Although correction models dealing with eccentricity have been available for decades, it is mostly seen as a planning task in which the aim is to choose the target size small enough so that the resulting eccentricity error remains negligible. Besides the fact that advanced mathematical models are available and that the influence of this error on camera calibration results is still not completely investigated, there are various additional reasons why bigger targets can or should not be avoided. One of them is the growing image resolution as a by-product from advancements in the sensor development. Here, smaller pixels have a lower S/N ratio, necessitating more pixels to assure geometric quality. Another scenario might need bigger targets due to larger scale differences whereas distant targets should still contain enough information in the image. In general, bigger ellipses contain more contour pixels and therefore more information. This supports the target-detection algorithms to perform better even at non-optimal conditions such as data from sensors with a high noise level. In contrast to rather simple measuring situations in a stereo or multi-image mode, the impact

  3. CVD calibration light systems specifications. Rev. 0

    Energy Technology Data Exchange (ETDEWEB)

    Mcllwain, A. K. [Analytical Science Branch, Whiteshell Laboratories, AECL Research Pinawa, Manitoba (Canada)

    1992-04-15

    Two prototype Cerenkov Viewing Device Calibration Light systems for the Mark IV CVD have been fabricated. They consist of a maintenance unit that will be used by the IAEA maintenance staff and a field unit that will be used by IAEA inspectors. More detailed information on the design of the calibration units can be obtained from the document SSP-39 and additional information on the Mark IV CVD can be obtained from the operating manual published as Canadian Safeguards Support Program document CSSP 6. The specifications refer to the prototype units which will be demonstrated to the IAEA in 1992 May. Based upon the feedback from the IAEA, the instruments will be changed in the final production models to provide devices that more closely satisfy the needs of the end users.

  4. Gravimetric gas determinations for volume calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, P.W.

    1991-12-31

    Gravimetric measurement of gases is one of the methods available for calibrating gas volumes. By inputting a known quantity of gas and measuring the resulting pressure and temperature, the system volume can be calculated using gas law principles. Historically, this method has been less accurate due to the difficulty in the mass determination. This difficulty comes from several sources. Two examples are the large tare weight of the gas container relative to the weight of gas and the external volume of the gas container relative to the standards. The application of a gravimetric gas determination to tank volume calibrations at the Savannah River Site is discussed. Mass determinations on a 25,000 gram gas container were such that a 1500 gram quantity of gas was routinely determined to within {plus_minus}0.2 gram at the 99% confidence level. The weighing design and the methods used to address the difficulties of the mass determination are detailed.

  5. Calibration of Flow Cytometry for Quantitative Quantum Dot Measurements.

    Science.gov (United States)

    Mittal, Rowena; Bruchez, Marcel P

    2009-07-01

    Observations of quantum dot (QD) labeled cells in biomedical research are mainly qualitative in nature, which limits the ability of researchers to compare results experiment-to-experiment and lab-to-lab to improve the state-of-the-art. Labeled cells are useful in a range of in vitro and in vivo assays where tracking behavior of administered cells is integral for answering research questions in areas such as tissue engineering and stem cell therapy. Before the full potential of QD based toolsets can be realized in the clinic, uptake of QDs by cells must be quantified and standardized. This unit describes a novel, simple method to assess the number of QDs per cell using flow cytometry and commercially available standards. This quick and easy method can be used by all researchers to calibrate their flow cytometry instruments and settings, and quantify QD uptake by cells for in vitro and in vivo experimentation for comparable results across QD conjugate types, cell types, research groups, lots of commercial QDs, and homemade QDs.

  6. An Accurate Projector Calibration Method Based on Polynomial Distortion Representation

    OpenAIRE

    Liu, Miao; Sun, Changku; Huang, Shujun; Zhang, Zonghua

    2015-01-01

    In structure light measurement systems or 3D printing systems, the errors caused by optical distortion of a digital projector always affect the precision performance and cannot be ignored. Existing methods to calibrate the projection distortion rely on calibration plate and photogrammetry, so the calibration performance is largely affected by the quality of the plate and the imaging system. This paper proposes a new projector calibration approach that makes use of photodiodes to directly dete...

  7. Calibrating pen dosimeters with and without a phantom

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda B.C.; Cescon, Claudinei T.; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: ctcescon@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Thirty one direct reading dosimeters (pen dosimeters) were calibrated and tested in standard beams of gamma radiation, with and without the use of a phantom. The calibration was performed with a Co-60 source and tested with a Cs-137 source. The dose-response curves of the pen dosimeters and their calibration factors for a Co-60 source, with and without the use of a phantom were obtained. The results show the need to calibrate the pen dosimeters with a phantom. (author)

  8. Calibrated Weighting for Small Area Estimation

    OpenAIRE

    Chambers, R. L.

    2005-01-01

    Calibrated weighting methods for estimation of survey population characteristics are widely used. At the same time, model-based prediction methods for estimation of small area or domain characteristics are becoming increasingly popular. This paper explores weighting methods based on the mixed models that underpin small area estimates to see whether they can deliver equivalent small area estimation performance when compared with standard prediction methods and superior population level estimat...

  9. Absolute Radiometric Calibration of KOMPSAT-3A

    Science.gov (United States)

    Ahn, H. Y.; Shin, D. Y.; Kim, J. S.; Seo, D. C.; Choi, C. U.

    2016-06-01

    This paper presents a vicarious radiometric calibration of the Korea Multi-Purpose Satellite-3A (KOMPSAT-3A) performed by the Korea Aerospace Research Institute (KARI) and the Pukyong National University Remote Sensing Group (PKNU RSG) in 2015.The primary stages of this study are summarized as follows: (1) A field campaign to determine radiometric calibrated target fields was undertaken in Mongolia and South Korea. Surface reflectance data obtained in the campaign were input to a radiative transfer code that predicted at-sensor radiance. Through this process, equations and parameters were derived for the KOMPSAT-3A sensor to enable the conversion of calibrated DN to physical units, such as at-sensor radiance or TOA reflectance. (2) To validate the absolute calibration coefficients for the KOMPSAT-3A sensor, we performed a radiometric validation with a comparison of KOMPSAT-3A and Landsat-8 TOA reflectance using one of the six PICS (Libya 4). Correlations between top-of-atmosphere (TOA) radiances and the spectral band responses of the KOMPSAT-3A sensors at the Zuunmod, Mongolia and Goheung, South Korea sites were significant for multispectral bands. The average difference in TOA reflectance between KOMPSAT-3A and Landsat-8 image over the Libya 4, Libya site in the red-green-blue (RGB) region was under 3%, whereas in the NIR band, the TOA reflectance of KOMPSAT-3A was lower than the that of Landsat-8 due to the difference in the band passes of two sensors. The KOMPSAT-3Aensor includes a band pass near 940 nm that can be strongly absorbed by water vapor and therefore displayed low reflectance. Toovercome this, we need to undertake a detailed analysis using rescale methods, such as the spectral bandwidth adjustment factor.

  10. MAGNETIC GRADIOMETRY: Instrumentation, Calibration and Applications

    DEFF Research Database (Denmark)

    Merayo, Jose Maria Garcia

    independent Compact Spherical Coil (CSC) sensors are set up on an optical bench at a distance of 60cm. Each of the magnetometers is calibrated separately and has an absolute accuracy better than 0.2nT. The controlling electronics has been designed with space specifications and the same instrumentation....... GRADSAT, two 20km separated magnetic instrumented satellites, combines state-of-the-art technology with advanced instrumentation to produce world class science....

  11. Absolute Radiometric Calibration of KOMPSAT-3A

    Directory of Open Access Journals (Sweden)

    H. Y. Ahn

    2016-06-01

    Full Text Available This paper presents a vicarious radiometric calibration of the Korea Multi-Purpose Satellite-3A (KOMPSAT-3A performed by the Korea Aerospace Research Institute (KARI and the Pukyong National University Remote Sensing Group (PKNU RSG in 2015.The primary stages of this study are summarized as follows: (1 A field campaign to determine radiometric calibrated target fields was undertaken in Mongolia and South Korea. Surface reflectance data obtained in the campaign were input to a radiative transfer code that predicted at-sensor radiance. Through this process, equations and parameters were derived for the KOMPSAT-3A sensor to enable the conversion of calibrated DN to physical units, such as at-sensor radiance or TOA reflectance. (2 To validate the absolute calibration coefficients for the KOMPSAT-3A sensor, we performed a radiometric validation with a comparison of KOMPSAT-3A and Landsat-8 TOA reflectance using one of the six PICS (Libya 4. Correlations between top-of-atmosphere (TOA radiances and the spectral band responses of the KOMPSAT-3A sensors at the Zuunmod, Mongolia and Goheung, South Korea sites were significant for multispectral bands. The average difference in TOA reflectance between KOMPSAT-3A and Landsat-8 image over the Libya 4, Libya site in the red-green-blue (RGB region was under 3%, whereas in the NIR band, the TOA reflectance of KOMPSAT-3A was lower than the that of Landsat-8 due to the difference in the band passes of two sensors. The KOMPSAT-3Aensor includes a band pass near 940 nm that can be strongly absorbed by water vapor and therefore displayed low reflectance. Toovercome this, we need to undertake a detailed analysis using rescale methods, such as the spectral bandwidth adjustment factor.

  12. Electroweak Calibration of the Higgs Characterization Model

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    I will present the preliminary results of histogram fits using the Higgs Combine histogram fitting package. These fits can be used to estimate the effects of electroweak contributions to the p p -> H mu+ mu- Higgs production channel and calibrate Beyond Standard Model (BSM) simulations which ignore these effects. I will emphasize my findings' significance in the context of other research here at CERN and in the broader world of high energy physics.

  13. Magnetic Test Facility - Sensor and Coil Calibrations

    Science.gov (United States)

    2013-08-01

    stray capacitance and resistance of the system. These sensors are unlikely to be useful in the measurement of sub 1 Hz signals due to the small...technique to accelerometers . Their results show the neces- sity of calibrating in the absence of any ferromagnetic or high permeability materials, in...Crotti et al. (2006) investigate a coil’s frequency re- sponse, and how it is impacted by inter-winding inductance and capacitance and the skin effect

  14. Precision Calibration of Infrared Synchrotron Radiation Detectors

    CERN Document Server

    Maltsev, A A; Maslova, M V

    2003-01-01

    The technique of calibration of synchrotron radiation precision detectors on a tungsten source based on similarity (close similarity) of character of spectral distributions of synchrotron and thermal radiations is given. The characteristics of various commonly used lamps, used as "standard" ones, are given. The errors of measurements are analyzed. The detectors are intended for absolute measurements of the number of electrons in a ring-shaped bunch.

  15. Calibration set up for load cells

    Science.gov (United States)

    Rao, T. V. Govinda; Venkatesh, C. S.; Shivashankar, N.

    1989-05-01

    The planning, designing, fabrication, and calibration of 30, 50, and 100 ton tension load cells and 30 ton shear load cells are described. The tension load cells are for monitoring the force developed by earth moving vehicles and the shear load cells are for monitoring the load that tipplers unload form platform to ground. The shear load cells were incorporated into a rotary wagon tippler.

  16. Calibration and Propagation of Uncertainty for Independence

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Troy Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kress, Joel David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bhat, Kabekode Ghanasham [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-30

    This document reports on progress and methods for the calibration and uncertainty quantification of the Independence model developed at UT Austin. The Independence model is an advanced thermodynamic and process model framework for piperazine solutions as a high-performance CO2 capture solvent. Progress is presented in the framework of the CCSI standard basic data model inference framework. Recent work has largely focused on the thermodynamic submodels of Independence.

  17. A miniaturized self-calibrated pyrometer microsystem

    OpenAIRE

    Gonçalves, L.M.; Gomes, L. G.; Ribeiro, S. F.; Couto, Carlos; Correia, J.H.

    2003-01-01

    paper describes the design, modeling and optimization of a miniaturized self-calibrated pyrometer to detect infrared radiation (in 5-20 µm range of wavelengths) in order to measure the real temperature of objects without contact. The microsystem consists of a thermally insulated absorbing area and two thermopiles with the hot junctions in the absorbing area and the cold junctions on a heat sink (i.e. the silicon bulk). The complete microsystem is in silicon planar technology and each therm...

  18. Bathymetry Estimations Using Vicariously Calibrated HICO Data

    Science.gov (United States)

    2013-07-16

    Process Exemplar (HOPE) algorithm, which along with other absorption and backscattering values, estimates bottom albedo and water depth. Vicarious...algorithm, which along with other absorption and backscattering values, estimates bottom albedo and water depth. Vicarious calibration uses in situ...the 1 km or 250 m spatial resolution of MODIS , this higher spatial resolution allows HICO data to be used to generate more relevant information

  19. Absorptive Capacity and Diversity

    DEFF Research Database (Denmark)

    Kristinsson, Kári

    with the arguments put forth by Cohen and Levinthal and subsequent researchers, but has not been verified empirically before. Second, the relationship between the diversity of individuals and innovative performance and idea generation is moderated by adherence to goals. This result might help to explain...... the inconsistencies in prior research on diversity. Third, when we find that educational diversity increases the number of ideas and their quality in idea generation teams. Our results suggest that teams with a diverse knowledge base generate more and better ideas than more homogenous teams. With an experimental...

  20. Total Measurement Uncertainty for the Plutonium Finishing Plant (PFP) Segmented Gamma Scan Assay System

    CERN Document Server

    Fazzari, D M

    2001-01-01

    This report presents the results of an evaluation of the Total Measurement Uncertainty (TMU) for the Canberra manufactured Segmented Gamma Scanner Assay System (SGSAS) as employed at the Hanford Plutonium Finishing Plant (PFP). In this document, TMU embodies the combined uncertainties due to all of the individual random and systematic sources of measurement uncertainty. It includes uncertainties arising from corrections and factors applied to the analysis of transuranic waste to compensate for inhomogeneities and interferences from the waste matrix and radioactive components. These include uncertainty components for any assumptions contained in the calibration of the system or computation of the data. Uncertainties are propagated at 1 sigma. The final total measurement uncertainty value is reported at the 95% confidence level. The SGSAS is a gamma assay system that is used to assay plutonium and uranium waste. The SGSAS system can be used in a stand-alone mode to perform the NDA characterization of a containe...